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Service Manual - SRS Airbag, Safety Belts and Bunk Restraints

1. Ignition ON Ignition position Re connect the battery negative lead Read off the fault codes No active fault code Breakage in the airbag module Change the airbag module The same fault code There is no fault in the MID 232 SID 1 FMI 5 airbag module con is displayed tinue with step 2 36 Group 88 SRS Airbag Safety Belts and Bunk Restraints Troubleshooting Step 2 Ignition OFF Disconnect test resistor 9988695 Disconnect the contact reel With the ignition cable disconnected from the contact reel OL or OC Bad contact reel Change the con measure resistance between the terminals on the contact open circuit tact reel reel Measure with one probe at the airbag module con P A Bad ignition cable Check the cable nector and the other probe at the ignition cable terminal on the contact reel harness go to step 3 Measure resistance across ter 45 50 KQ Bad contact reel Check the con minals 1 and 2 on the ignition tact reel go back cable connector to step 2 OL or OC Open circuit in the Check the cable open circuit ignition cable or harness go to ECU step 4 W8001343 Step 4 e Ignition OFF Disconnect the ignition cable from the ECU Measure resistance across ter OL or OC Bad cable harness Replace the ca minal 1 on the ignition cable open circuit ble harness connector to terminal 10 at the ECU connector Use tool J 42449 1 to connect a test
2. 14 Service Procedures Group 88 SRS Airbag Safety Belts and Bunk Restraints Service Procedures 8844 03 02 02 Upper Bunk Restraint Replacement VN 770 Bunk restraint Restraint latch assembly Side tether assembly Restraint buckle assembly 1 2 3 4 75 Group 88 SRS Airbag Safety Belts and Bunk Restraints AN DANGER It is critical that any time a vehicle has been involved in an accident the entire safety belt system must be replaced in the vehicle which also includes the sleeper bunk restraints if they were in use at the time of the accident Failure to replace the safety belt sys tem may result in serious injury or death AN DANGER Before working on a vehicle set the parking brakes place the transmission in neutral and block the wheels Failure to do so can result in unexpected vehicle movement and can cause serious personal in jury or death AN DANGER When installing safety belt components do not over torque or use high speed pneumatic tools Doing so may cause anchor point failures resulting in the possible failure of the safety belt anchoring system which can cause serious personal injury or death Removal 1 Remove the bunk restraint 1 by re leasing the 6 buckles 2 Remove the nut securing the restraint latches 2 on the rear wall 3 Remove the bolts securing the left and right side tether brackets 3 4 Remove the screws and bumper stops around the back and sides of
3. 27273 X hallen S 405 08 Gothenburg Sweden 46 Troubleshooting T8006872 Group 88 SRS Airbag Safety Belts and Bunk Restraints Safety Belts and Bunk Re straints Inspection AN DANGER Before working on a vehicle set the parking brakes place the transmission in neutral and chock the wheels Failure to do so can result in unexpected vehicle movement and can cause serious personal in jury or death AN DANGER Failure to properly inspect and maintain safety belts can cause serious injury or loss of life AN DANGER It is critical that any time a vehicle has been involved in an accident the safety belt system in use at the time of the accident must be replaced including the sleeper bunk restraints if they were in use at the time of accident Failure to replace the safety belt system may result in serious injury or death AN DANGER Safety belts must be inspected at the scheduled pre ventive maintenance inspection or more often if exposed to severe environmental or vocational condi tions Failure to replace a worn or damaged seat belt assembly may result in serious injury or death Note If replacement of any part of the seat is indicated through maintenance guidelines below the entire belt as sembly must be replaced both retractor and buckle side Troubleshooting W8001406 Check the web wear at the latch area The webbing must be closely exam ined to determine if there are any cuts
4. Checking page 21 If resistance is ok connect the tool to the connector where the airbag module was removed Ignition ON Ignition position Connect the battery negative lead Read off the fault codes No active fault code Short circuiting to voltage or Change the airbag mod ground in the airbag module ule The same fault code There is no fault in the airbag Continue with step 2 SID 1 FMI 4 is shown module The same fault code Skip to step 3 SID 1 FMI 3 is shown 40 Group 88 SRS Airbag Safety Belts and Bunk Restraints Troubleshooting Step 2 Ignition OFF Disconnect test resistor 9988695 Disconnect the contact reel Measure resistance in the igni One or two mea Short circuiting Change the cable tion cable connector harness surements give a in the ignition harness side Measure resistance from value of O Q cable terminal 1 to a known ground Then measure from terminal 2 to a known ground Terminal 1 Short circuiting Change the con 45 50 kQ to ground tact reel Terminal 2 92 98 kQ W8001343 Step 3 e Ignition OFF Disconnect the battery negative lead Disconnect the contact reel Ignition ON Measure resistance in the ignition 45 50 kQ for both Bad contact Change the con cable connector harness side measurements reel tact reel Measure resistance from terminal 1 using the meter s red test lead to a known power source with the blac
5. because the power locks may lock the doors when the battery is reconnected Then connect the negative battery lead and torque to 24 27 Nm 18 20 ft lb 22 View fault codes to see if any appear If faults were present before replacing the components they are still present as inactive faults Clear the inactive faults There should be no active fault codes for the SRS system If any active fault codes are present they need to be re paired Note If either of the fault codes MID 232 SID 240 FMI 14 or MID 232 SID 254 FMI 12 is present replace the SRS ECU see SRS ECU Replace ment page 57 Group 88 SRS Airbag Safety Belts and Bunk Restraints i 8847 03 02 01 SRS ECU Replacement Before starting any service procedure see e General Work Practices page 51 Important Only certified technicians may work on the SRS AN DANGER Before working on a vehicle set the parking brakes place the transmission in neutral and block the wheels Failure to do so can result in unexpected vehicle movement and can cause serious personal in jury or death Removal 1 Turn the ignition switch OFF 2 Remove the lower dash panels center and right sections by removing the 8 torx bolts and 4 plastic nuts AN PS F Wwe ON iN W8001295 Remove the 2 torx bolts in the SRS ECU cover and remove the cover Service Procedures 4 NN WW INS lt AE MZ oe W8001296 Remove the 3 torx
6. Display as ac tive or inactive After repairs have been made the fault will be shown as inactive The SRS lamp will remain on until the fault is cleared Group 88 SRS Airbag Safety Belts and Bunk Restraints Design and Function SRS Indicators vehicles built from 3 99 Unlike the earlier instrumentation there is no SRS indi cator lamp The SRS or airbag icon is only shown in the graphic display 1 and does not appear when the igni tion key is turned on The INFO telltale lamp 2 will illuminate at key on during the bulb check along with all the other telltale bulbs in the instrument cluster Vehicles equipped with instrumentation built since 3 99 will display the airbag icon in the graphic display if a fault active or inactive is detected in the SRS system Addi tionally the INFO telltale lamp will illuminate Gs W8002902 1 SRS Indicator 2 INFO Telltale Lamp 16 Group 88 SRS Airbag Safety Belts and Bunk Restraints Diagnostic System with Fault Codes The SRS control unit has a built in diagnostic system A microprocessor in the control unit continuously monitors the SRS system If an active fault occurs this is broad cast on the J1587 data link as an active fault code and the SRS indicators in the instrument cluster are illumi nated In spite of this the system will try to activate the airbag in the event of a collision unless the wire to the SRS module has been damaged If the SRS lamp re mains
7. E N RAR RS E Upper Bunk Restraint Replacement VN GTOGOD aaa Upper Bunk Restraint Replacement WEL GZO iS Feedback Operation Numbers Group 88 SRS Airbag Safety Belts and Bunk Restraints General General SRS Airbag Safety Belts and Bunk Restraints W8001290 W8001834 SRS Airbag Safety Belt This publication contains service information about the safety belts bunk restraints and supplemental restraint system It is intended for use by service technicians who have attended and received certification in the Volvo Truck Supplemental Restraint System class 88A The service procedures and fault tracing instructions may only be carried out by certified technicians Volvo Trucks North America Inc will not assume any liabil ity whatsoever for damage incurred either damage to materials or personal injury which may result if the service procedures are not followed or if the work is carried out by non certified personnel Group 88 SRS Airbag Safety Belts and Bunk Restraints SRS Components Torque Values Specifications Airbag module 10 2Nm 89 18 in lb Contact reel 5 0 8 Nm 44 in lb Control unit 10 2Nm 89 18 in lb Control unit cover 10 2Nm 89 18 in lb Safety Belts and Bunk Restraints Torque Values Steering wheel center bolt 85 15 Nm 63 11 ft lb Steering column covers 5 0 8 Nm 44 7 in lb Saf
8. Remove one bolt from each side of the restraint brackets in the roof 2 Remove the restraint Group 88 SRS Airbag Safety Belts and Bunk Restraints W8002924 1 Zipper 2 Mounting bracket 3 Buckle assembly Unzip 1 the cover on the top bunk and flip the bunk to the upright posi tion Remove the restraint mounting bracket bolts 2 from the rear wall one on each side 3 Remove the mounting rivets or screws 3 from the buckle assembly in the bottom of the bunk 2 on each side Pull on the buckle assembly to remove it feeding the bracket through the back side Installation 4 Install the restraint brackets through 68 7Nm the front of the bunk by reaching 50 5 ft lb through the back of the bunk and feed ing the restraint bracket through the hole in the back of the bunk Install the bolt and align the bracket to the rear wall Torque to 68 7 Nm 50 5 ft Ib Service Procedures 5 Note Steel rivets of the proper size Volvo P N 3082569 or equivalent must be used Rivet the buckle assemblies to the bot tom of the bunk Zip up the top bunk cover 73 Group 88 SRS Airbag Safety Belts and Bunk Restraints 6 Install the bunk restraint brackets to the roof by installing the bolt through the short buckle and restraint bracket on the left and right side Align to the correct position and torque to 68 7 Nm 50 5 ft lb 7 Install the latches into the buckles at the front of the bunk
9. SRS ECU electrical con nector making certain the locking arm is pulled back onto the locking tab Connect the SRS wiring harness to the main cab harness connector making certain the connector lock is installed 12 If the ECU cover was removed install it with the 2 mounting bolts Torque to 10 2 Nm 88 18 in lb 13 W8001460 Secure the SRS harness with tie straps to the fastening clips around the SRS ECU 14 Route the SRS harness along the main cab harness over to the steering column 61 Group 88 SRS Airbag Safety Belts and Bunk Restraints Service Procedures 15 16 w O Z N WARNING eRe Make sure that no one is inside the cab when con necting the battery and that the cab doors and driver side window are closed Otherwise personal injury or K S ES T mm te death may result due to possible deployment of the Ri E AN CAUTION ele SB If there are other ground cables connected to the bat tery such as engine ECU satellite system etc connect the battery ground cable first then connect those grounds Electronic modules may be damaged when additional grounds are connected disconnected without the main battery ground connected Turn the ignition switch to the ON posi tion Make sure nobody is in the cab Close the cab windows and doors but leave the passenger side window open because the power locks may lock the doors when the battery is reconnected Then connect the
10. The Airbag Module Contains an electric ignition device igniter gas generator inflatable bag In the event of a collision that is of a high enough G force and duration the control unit sends electrical im pulses to the electric igniter A which activates the gas generator The gas generator B in the airbag module is an en closed unit which is filled with a propellant which forms a harmless gas When the gas generator is activated the airbag is very quickly filled by the gas The airbag is folded up and lies above the gas genera tor A fully inflated bag has a volume of approximately 67 liters The airbag is made from a strong polyamide weave with two evacuation holes The ventilation through the evacu ation holes allows the bag to collapse at a suitable speed that retards the forward movement of the driver AN DANGER An airbag module must never be taken apart At tempting to take apart an airbag module which has not been deployed could deploy the airbag causing serious personal injury or death Attempting to take apart an airbag module which has been deployed could cause chemical burns or skin ir ritation Airbag module A Electric igniter B Gas generator Design and Function W8001292 W8001294 Group 88 SRS Airbag Safety Belts and Bunk Restraints Airbag Module Connector The airbag module connector has two built in capacitors C1 blocks DC voltage and prevents the igniter from ig
11. against the bottom edge of the element using a cotter pin puller or other sharp small diameter tool 3 Pull the element from the resistor housing but do not push against the resistor pins When removing the element the retainer ring may lift if so push the retainer back into place The white powder residue from a deployed airbag can be an irritant to skin and tissue To avoid injury wear gloves and a dust mask when handling a deployed module and avoid getting this white powder in eyes or on skin If skin irritation occurs immediately flush the skin with water Seek medical attention if irritation continues W8001352 Removing the short circuit element 21 Group 88 SRS Airbag Safety Belts and Bunk Restraints Troubleshooting Measuring the Resistance Use an ohmmeter to measure the resistance in the test resistor Measure over the pins as indicated in the illustration The ohmmeter should show between 1 8 and 2 5 Q e Ifthe Value Agrees There is no fault on the test resistor e If the Value Deviates If the ohmmeter reading deviates from the expected value the test resistor is defective Discard the test T8006865 resistor and replace it with a new one Measure the resistance Connecting the Test Resistor AN DANGER To avoid injury the battery must not be connected when the airbag module is being removed or installed If the battery is connected deployment of the airbag may occur possibly caus
12. fault is localized See Routines for a Damaged Faulty Airbag Module page 46 concerning the handling of a damaged airbag module Troubleshooting T8006872 39 Group 88 SRS Airbag Safety Belts and Bunk Restraints Troubleshooting Fault Code MID 232 SID 1 FMI 4 3 Driver Side Igniter Loop Voltage Shorted Low High Before disconnecting or connecting the airbag mod ule turn the ignition key OFF and remove the battery AN DANGER ground cable Remove the airbag module and install the test resistor when troubleshooting the wiring harness for the SRS AN CAUTION system Failure to do so could cause the airbag to de ploy during troubleshooting causing serious personal If there are other ground cables connected to the bat injury or death tery such as engine ECU satellite system etc disconnect those grounds first then remove the bat tery ground cable Electronic modules may be damaged when additional grounds are con AN WARNING nected disconnected without the main battery ground connected Always disconnect the main battery To avoid injury the battery must not be connected ground last when the airbag module is being removed or installed If the battery is connected deployment of the airbag may occur possibly causing personal injury or death Step 1 e Ignition OFF Disconnect the battery negative lead Disconnect the airbag module Check resistance of test resistor 9988695 see Test Resistor
13. to 3 99 The SRS system is continuously monitored by micropro cessors in the control unit If a fault occurs this is stored in the memory as an active fault code At the same time the SRS indicator lamp in the instrument cluster is acti vated When the ignition key is turned ON the SRS indicator lamp lights together with the other lamps in the instru ment cluster and goes out after 10 seconds If the SRS indicator lamp does not go out as described above or lights up during driving there is an active fault in the SRS system see Troubleshooting When the control unit detects a fault the SRS indicator lamp lights until the fault is repaired and the inactive fault code cleared AGNOSTIC MESSAGES W8001333 Graphic Display prior to 3 99 The instrument cluster is equipped with an LCD display that is located to the left of the steering column This Graphic Display is used to display messages and faults from the various electronic control units and components on the truck During normal operation the SRS indicator lamp in the instrument cluster will illuminate for 10 seconds after ig nition The lamp will go out if the system is functioning normally If a fault is detected in the SRS system an active fault code will be logged into the SRS control unit Then the SRS lamp in the instrument cluster will illuminate The fault may be accessed by using the Graphic Display SRS faults will be shown in the Graphic
14. to pass through the hole in the steering wheel 12 Failure to secure the contact reel label to the contact reel may result in damage to the contact reel Do not turn the steering wheel while the contact reel is se cured Turning the wheel or shaft can damage the contact reel If installing a new contact reel disregard this caution Gently secure the contact reel label to the contact reel using the screw in the end of the label Group 88 SRS Airbag Safety Belts and Bunk Restraints 13 W8001308 Disconnect the connectors for the con tact reel ignition cable and horn contacis 14 W8001309 Remove the 3 torx bolts from the con tact reel Service Procedures W8001305 Remove the contact reel assembly Installation W8001305 0 8 Nm 7i Install the new contact reel assembly 5 onto the steering shaft and tighten the 44 3 torx bolts to 5 0 8 Nm 44 7 in lb Connect the connectors for the horn and the airbag module 17 Install the front and rear steering col umn covers Torque bolts to 5 0 8 Nm 44 7 in lb Pull the rub ber grommets over the covers at the stalk switches Install the plastic clips at the bottom of the covers 55 Group 88 SRS Airbag Safety Belts and Bunk Restraints 18 Service Procedures 21 Personal injury risk Make sure that no one is inside the cab when connecting the battery and that the cab doors and driver side window are closed Otherw
15. 65 Group 88 SRS Airbag Safety Belts and Bunk Restraints W8002922 1 and 2 are bolts Remove the recoiler bolt 1 Remove the trim cap on the D ring hex bolt and remove the bolt 2 W8001330 Remove the bolt mounting the safety belt to the seat Remove the bolt to the outside and rear of the seat 5 Remove the 5 screws from the bottom inner seat side cover on the latch side of the seat 66 Service Procedures W8001327 Remove the latch assembly from the inner rear bottom of the seat Installation 7 Install the latch assembly on the inner rear bottom of the seat Torque to 50 10 Nm 442 80 in lb 8 Install the inner bottom seat side cover with 5 screws 1 1 and 2 are bolts Install the bolt 1 into the recoiler Torque to 50 10 Nm 442 80 in lb Install the hex bolt 2 in the D ring and torque to 50 10 Nm 442 80 in lb 50 10 Nm 442 80 in lb W8002922 Group 88 SRS Airbag Safety Belts and Bunk Restraints 10 Install the safety belt bolt and mount to the outer rear bottom of the seat Torque to 50 10 Nm 442 80 in lb 11 Install the outer bottom seat side cover with 5 screws 12 W8001329 Install the seat cushion by aligning clips and snapping into place Service Procedures 67 Group 88 SRS Airbag Safety Belts and Bunk Restraints 8844 03 02 01 Service Proc
16. 7 Turn the key to the ON position Use the Esc button to access the main menu structure Select Password Input Use the 1 or Select and Up Down buttons to enter the 4 digit numerical password The factory default password is 1234 If the vehicle owner has input another password it must be entered For more password information see service information on the Instrumentation in Group 38 After the password has been entered select System Diagnostics Fault Diagnostics Reset All Reset Press FOR 1S Press and hold the 1 or Select button for 1 sec ond When the faults are cleared Data Transfer Complete will be displayed on the graphic display screen Data transfer completed To exit press the Esc button as needed to return to the main menu Group 88 SRS Airbag Safety Belts and Bunk Restraints Reading Clearing Fault Codes with VCADS Pro VCADS Pro is a Windows 95 based tool that can be used to read and clear the SRS ECU MID 232 fault codes on vehicles built since 3 99 The following is a brief description of the fault code retrieval clearing process For more detailed information see the most re cent VCADS Pro user manual or the help menu in the tool itself Y VCADS Pro TestiCalibration Troubleshooting W0001632 File Action Test Options Help e HS lua Ol O 2 ll eee Numb
17. 8006872 35 Group 88 SRS Airbag Safety Belts and Bunk Restraints Troubleshooting Fault Code MID 232 SID 1 FMI 5 Driver Side Igniter Loop Current Low Open Circuit Before disconnecting or connecting the airbag mod ule turn the ignition key OFF and remove the battery AN DANGER ground cable Remove the airbag module and install the test resistor when troubleshooting the wiring harness for the SRS AN CAUTION system Failure to do so could cause the airbag to de ploy during troubleshooting causing serious personal If there are other ground cables connected to the bat injury or death tery such as engine ECU satellite system etc disconnect those grounds first then remove the bat tery ground cable Electronic modules may be damaged when additional grounds are con N WARNING nected disconnected without the main battery ground connected Always disconnect the main battery To avoid injury the battery must not be connected ground last when the airbag module is being removed or installed If the battery is connected deployment of the airbag may occur possibly causing personal injury or death Step 1 e Ignition OFF Disconnect the battery negative lead Remove the airbag module Disconnect the connector from the airbag module Check resistance of test resistor 9988695 see Test Resistor Checking page 21 If resistance is ok connect the tool to the connector where the airbag module was removed
18. Conditions for fault code If the SRS ECU registers a crash condition fault code MID 232 SID 240 FMI 14 is generated Note that this fault code s description appears differently in the Pro link and instrument cluster In the Pro link the fault code is described as SAS Airbag Crash Event Stored special instructions In the instrument cluster it may be either way shown below D AIRBAG UNKNOWN A SPECIAL INSTRUCTIONS G ACTIVE N Air bag Program memory Unknown fault Active 1 mM Action Replace the SRS ECU contact reel wiring harness airbag module steering wheel and safety belts including the bunk restraint if it was in use See Service Proce dures for more information Troubleshooting T8006850 43 Group 88 SRS Airbag Safety Belts and Bunk Restraints Troubleshooting Faults Which Do Not Generate a Fault Code Certain faults can occur without receiving any direct information via a fault code To find the cause of the fault fault tracing must be carried out step by step SRS Lamp Does not Light 0 Conditions for Fault vehicles built before 3 99 o The lamp should normally illuminate when the ignition is ON and go out after 10 seconds W3000982 During that 10 seconds the SRS self diagnosis is being SRS lamp carried out After the self diagnosis is complete the con trol unit reduces the voltage to the indicating circuit to approximately 0 8 2 0 V and the l
19. DANGER When installing safety belt components do not over torque or use high speed pneumatic tools Doing so may cause anchor point failures resulting in the possible failure of the safety belt anchoring system which can cause serious personal injury or death 63 Group 88 SRS Airbag Safety Belts and Bunk Restraints Service Procedures Removal 2 Remove the bolt cap and the torx bolt 1 for the shoulder harness D ring 2 3 W8002894 koj 1 Hex box 2 Bol 3 Hex box W8002921 4 Bol 1 Hex box 2 Shoulder harness D ring Remove the hex bolt 1 in the outer side of the seat fastening the seat belt bracket and tether belt Remove the bolt 2 fastening the tether belt to the floor Remove the recoiler cover by pulling the cover from the bottom With the cover removed remove the hex bolt 1 from the recoiler 4 Remove the hex bolt 3 on the inner side of the seat to remove the buckle assembly and tether belt Remove the bolt 4 fastening the tether belt to the floor on the inner side of the seat see illustration in previous step 64 Group 88 SRS Airbag Safety Belts and Bunk Restraints Service Procedures Installation 8841 03 02 01 Safety Belt Replacement One 5 Install the buckle and tether belt to the 68 7 Nm inner side of the seat Then install the 50 5 ft lb Volvo Seat bolt for the tether belt in the floor Torque bolts to 68 7 Nm 50 5 ft lb AN DANGER
20. ECU has detected a crash The SRS ECU airbag module contact reel steering wheel and safety belts must be replaced after a crash If the bunk restraint was in use it must also be replaced Note Do not clear fault code MID 232 SID 254 FMI 12 Controller 1 bad device Replace the SRS ECU see SRS ECU Replacement page 57 Group 88 SRS Airbag Safety Belts and Bunk Restraints Reading Fault Codes vehicles built from 3 99 Troubleshooting Vehicles built after 3 99 with a Volvo engine and after 5 99 with other engines will display the airbag icon in the graphic display 1 if a fault active or inactive is detected in the SRS system The INFO telltale lamp 2 will also illuminate GIs 2 Using the Graphic Display Control Buttons W8002902 To manually interact with the graphic display the wiper stalk switch on the right hand side of the steering wheel is used The following commands are available 1 LED 4 os 1 2 3 4 T3008810 Esc Escape is used to return to the previous menu and cancel a setting operation J or Select confirms a highlighted selection of a menu or character Up arrow moves the cursor up and is used when setting numerical values Down arrow moves the cursor down and is used when setting numerical values 27 Group 88 SRS Airbag Safety Belts and Bunk Restraints Reading Fault Codes with the Graphic Display The instrument cluster Graphic Disp
21. It is critical that any time a vehicle has been involved in an accident the entire safety belt system must be 6 Install the recoiler with the mounting bolt Install the recoiler cover Install the mounting bolt and D ring Torque bolts to 68 7 Nm 50 5 ft lb Install the mounting bolt cap replaced in the vehicle which also includes the sleeper bunk restraints if they were in use at the time of the accident Failure to replace the safety belt sys tem may result in serious injury or death AN DANGER 7 Install the safety and tether belt brack Before working on a vehicle set the parking brakes ets to the outer side of the seat place the transmission in neutral and block the Torque bolts to 68 7 Nm 50 5 ft wheels Failure to do so can result in unexpected lb Install the tether belt bracket in the vehicle movement and can cause serious personal in floor and torque the bolt to 68 7 Nm jury or death 50 5 ft lb AN DANGER When installing safety belt components do not over torque or use high speed pneumatic tools Doing so may cause anchor point failures resulting in the possible failure of the safety belt anchoring system which can cause serious personal injury or death Removal 1 Remove the bottom seat cushion by grasping at the front and rear of the cushion and pulling up W8001328 Remove the 5 screws from the bottom outer seat side cover
22. Service Manual Trucks Group 884 500 SRS Airbag Safety Belts and Bunk Restraints VN VHD 0 aa oe PV776 TSP1 44851 VOLVO Foreword The descriptions and service procedures contained in this manual are based on de signs and methods studies carried out up to April 2001 The products are under continuous development Vehicles and components produced after the above date may therefore have different specifications and repair methods When this is believed to have a significant bearing on this manual supplementary ser vice bulletins will be issued to cover the changes The new edition of this manual will update the changes In service procedures where the title incorporates an operation number this is a refer ence to an S R T Standard Repair Time Service procedures which do not include an operation number in the title are for gen eral information and no reference is made to an S R T The following levels of observations cautions and warnings are used in this Service Documentation Note Indicates a procedure practice or condition that must be followed in order to have the vehicle or component function in the manner intended Caution Indicates an unsafe practice where damage to the product could occur Warning Indicates an unsafe practice where personal injury or severe damage to the product could occur Danger Indicates an unsafe practice where serious personal injury or death could oc cur Volvo
23. Trucks North America Inc Greensboro NC USA Order number PV776 TSP144851 O 2001 Volvo Trucks North America Inc Greensboro NC USA All rights reserved No part of this publication may be reproduced stored in retrieval system or transmitted in any forms by any means electronic me chanical photocopying recording or otherwise without the prior written permission of Volvo Trucks North America Inc Contents A rara 3 SRS Airbag Safety Belts and Bunk Restraints 3 DPOCIMICALOMS cirios 5 SRS Components Torque Values cceeeeeee 5 Safety Belts and Bunk Restraints Torque Values 5 MOONS sport aa quisiera aaa rea da ca ca 7 Special Todle curar lid 7 Other Special Equipment oooccconcccnnccinncncnnncnncncnannnnnns 8 Design and Function ee eeeneeeeeeeeeeeeeeee 9 Safety Belts and Bunk Restraints 9 Supplemental Restraint System SRS 10 Sei COV STIG eines 10 Supplemental Restraint System SRS Compo HEME a ARAS 11 BRS Loto Unt TEGUA sra 11 Control Uni GONNeECtOr scan 12 Airbag Module iia 13 Airbag Module Connector coooccnnoccnonccnonncnoncnonnnnonoss 14 DONG REEI dp cccue a cucse la euass oe a IANDAS EO UANGA SPO ndsRS ada 14 SRS Indicators vehicles built prior to 3 99 15 SRS Indicators vehicles built from 3 99 16 Diagnostic System with Fault Codes 17 SRS Wing Hanes ria 17 Suppl
24. all Ib the covers if removed upper bunk models 8 Install the replacement restraint 68 7Nm latches on the rear wall Torque the 50 5 ft lb bolts to 68 7 Nm 50 5 ft lb 9 Install the replacement bunk restraint Check for proper fit and adjust as needed 71 Group 88 SRS Airbag Safety Belts and Bunk Restraints 8844 03 02 02 Service Procedures Upper Bunk Restraint Replacement VN 610 660 1 Upper bunk restraint buckle 2 Restraint brackets AN DANGER It is critical that any time a vehicle has been involved in an accident the entire safety belt system must be replaced in the vehicle which also includes the sleeper bunk restraints if they were in use at the time of the accident Failure to replace the safety belt sys tem may result in serious injury or death AN DANGER Before working on a vehicle set the parking brakes place the transmission in neutral and block the wheels Failure to do so can result in unexpected vehicle movement and can cause serious personal in jury or death 72 W8002920 AN DANGER When installing safety belt components do not over torque or use high speed pneumatic tools Doing so may cause anchor point failures resulting in the possible failure of the safety belt anchoring system which can cause serious personal injury or death Removal 1 Release the two buckles 1 on the front of the upper bunk restraint to re move the two latches
25. amp goes out When the lamp is on there is a voltage of approximately 12 V on the cable Conditions for Fault vehicles built after 3 99 The INFO lamp and all other telltales should illuminate 3 5 seconds when the ignition key is turned to ON to verify that the telltale bulbs operate Fault Symptom 1 The SRS INFO lamp is always out Cause of Fault Indicator lamp broken Incorrect voltage or improper ground in the instru ment cluster SRS Lamp Does not Light and Not Responding Message in Diagnostic Display Vehicles built before 3 99 only 1 The SRS lamp does not illuminate if the SRS is not installed in the vehicle 2 It also does not illuminate to indicate a breakage in the J1587 data link with the breakage occurring be fore the vehicle ignition is ON The lamp will still illuminate to indicate other faults and for 10 sec onds at ignition For these conditions when performing a diagnostic test on a vehicle without SRS the SRS diagnostic menu in the Pro link instrument cluster will display SRS AIRBAG NOT RESPONDING If condition 2 occurs check the data link connections and wiring 44 Group 88 SRS Airbag Safety Belts and Bunk Restraints Troubleshooting The SRS Lamp is Lighting but no Fault Code is Stored O IN Conditions for Fault vehicles built before 3 99 only The lamp should normally illuminate when the ignition is turned ON and go out after 10 seconds vee i a 5 SRS lamp Du
26. and right sections with 8 torx bolts and 4 plastic nuts Torque bolts to 3 5 0 5 Nm 31 4 5 in lb 3 5 0 5 Nm 31 4 5 in lb Group 88 SRS Airbag Safety Belts and Bunk Restraints 3741 03 02 01 SRS Wiring Harness Replace ment Only certified technicians may work on the SRS Important when replacing the SRS airbag wiring the harness must be installed and routed properly Wires may be pinched and broken when the steering column is adjusted if the harness is not routed and secured with tie straps as shown Damage to the wiring or connectors in the SRS must never be repaired spliced or partly replaced When a fault has been noted and localized in a certain connector or part of the SRS wiring harness the complete wire harness must be replaced Replace all tie straps removed when removing the har ness AN DANGER Failure to follow the routing shown when installing an SRS harness can result in damage to the wiring har ness and the SRS may not function which could result in serious injury or death in the event of an ac cident AN DANGER Before working on a vehicle set the parking brakes place the transmission in neutral and block the wheels Failure to do so can result in unexpected vehicle movement and can cause serious personal in jury or death Removal Electronic modules may be damaged when additional grounds connected to the battery such as engine ECU satellite system etc are connec
27. ayed D AIRBAG press the SET button RECEIVING DATA PLEASE WAIT will be displayed while the systems on the a DR AIRBAG IGN LOOP 31587 data link are polled 6 CURRENT LO GPEN C N INACTIVE Ne Eds W8001345 o Record all codes displayed 7 To display the next stored fault press the Down but ton For more information see Service information on Instrumentation in Group 38 25 Group 88 SRS Airbag Safety Belts and Bunk Restraints Clearing Fault Codes with a Pro link Faults can be cleared with the Pro link tool and Volvo cartridge All codes must be in an inactive state before clearing 1 Connect the Pro link to the diagnostic socket lo cated under the left side of the dash SRS AIRBAG A SELECTIONS CTIVE CODES SS EA W8001321 Turn the ignition on and follow the menus in the Pro link to SRS Airbag 3 Important Record all fault codes on the workorder before they are cleared They cannot be retrieved after clearing 26 Troubleshooting 4 After the SRS Airbag menu screen select the Diag nostics menu and Clear Codes 5 After codes have been successfully cleared Codes Cleared will be displayed on screen 6 Afinal check for fault codes should be carried out after clearing codes 7 The indicator lamp will go out when all codes are cleared Note Do not clear fault code MID 232 SID 240 FMI 14 Program memory Special instructions This code is present after an SRS
28. blies meet FMVSS 209 Type 1 and Type 2 requirements They are recommended for all per sons weighing over 25 kg 50 Ib A child restraint system should be used for each child weighing 25 kg 50 lb or less It should meet the require ments of FMVSS 213 Child Restraint System Carefully read and follow all manufacturer s instructions on instal lation and use Make certain the child remains in the restraint system at all times while the vehicle is in motion AN DANGER Safety belts must be properly worn at all times by the driver and all passengers while the vehicle is in motion even if the vehicle is equipped with a Supple ind mental Restraint System SRS or airbag Failure to do so can result in serious personal injury or death in the event of a collision Safety Belt The high mileage associated with heavy trucks the con tinual relative movement of the seat with the cab the possible contact with the vehicle seat or other parts of the cab structure make it crucial to inspect the safety belt system regularly See Safety Belts and Bunk Restraints Inspection page 47 for inspection instructions AN DANGER It is critical that any time a vehicle has been involved in an accident the safety belt system in use at the time of the accident must be replaced including the sleeper bunk restraints if they were in use at the time of the accident Failure to replace the safety belt sys tem may result in serio
29. bolts from the SRS ECU SS A N W8001297 Avoid touching the control unit contact pins There is a risk of damaging the control unit with electro static discharge Disconnect the SRS ECU electrical connector Push in on the tab holding the connector locking arm to release the connector 57 Group 88 SRS Airbag Safety Belts and Bunk Restraints Installation 6 Use only Volvo replacement parts and install the ECU only in the proper loca tion described below W8001296 Avoid touching the control unit contact pins There is a risk of damaging the control unit with electro static discharge Check the SRS ECU mounting plate for proper ground connection there should be no grease paint or dirt be tween the mounting plate and the cab body since the ECU is case grounded Install the SRS ECU to the mounting plate where the old ECU was with the 3 torx bolts Torque to 10 2 Nm 88 18 in lb 58 Service Procedures 1 Locking tab W8001322 2 Locking arm shown in unlocked position Connect the SRS ECU electrical con nector making certain the locking arm 2 is pulled back onto the locking tab 1 as shown in the illustration 9 Install the cover for the SRS ECU by installing one torx bolt on each side of the cover Torque to 10 2 Nm 88 18 in lb 10 Clear fault codes There should be no active fault codes for the SRS system 11 Install the lower dash panel center
30. ctive fault the fault is stored in the SRS con trol unit If the fault is inactive the dash indicator will still come on The dash indicator stays on until the inactive fault code is cleared 0 rt W300 SRS Indicator on dash 23 Group 88 SRS Airbag Safety Belts and Bunk Restraints Reading Fault Codes vehicles built before 3 99 Fault codes should be read with the MPSI Pro link 9000 The instrument cluster Graphic Display also displays fault codes Faults may be displayed as SAE J1587 text messages or numeric codes Reading Fault Codes with the Pro link 9000 1 24 The Pro link 9000 with the Volvo cartridge provides easy diagnosis of faults The Pro link includes an adapter for connecting the Pro link to the diagnostic socket The diagnostic socket is located under the left side of the dash After connecting the Pro link turn the ignition on and follow the menus in the Pro link to the SRS Airbag menu SRS AIRBAG 4 SELECTIONS 4 ACTIVE CODES W8001321 After the SRS Airbag menu screen ECU Informa tion and Diagnostics menus may be selected ECU Information provides hardware and software revision levels The Diagnostics menu allows a choice of Ac tive Codes Inactive Codes or Clear Codes 5 Troubleshooting SRS AIRBAG DRIVER IGNITER LOOP CURRENT LO OPEN C Al SIDA FAS ay MID description SID description FMI description A Active Inactive The number f
31. e the airbag module W8001302 6 Remove the 2 clips at the bottom of the steering column cover W8001294 AN DANGER Always store a non deployed airbag module with the metal underneath side down and in a place where it will not be handled carelessly This is to reduce the chance of the airbag being ejected from its storage position if accidentally deployed which could cause serious personal injury or death W8001303 Remove the rear steering column cover by removing the 3 torx bolts from the cover and sliding the rubber grommets off of the cover at the stalk switches Remove the 3 torx bolts from the front cover and remove the cover Cover the terminal opening with tape so that no particles metal filings etc can enter the module contact pins ig niter It is important that the airbag is stored in a secure place All airbag modules being replaced must be re turned to the manufacturer according to current procedures 53 Group 88 SRS Airbag Safety Belts and Bunk Restraints W8001300 W8001429 Unscrew the screw at the end of the contact reel caution label Leave the screw in the label to secure the screw in the contact reel after the steering wheel is removed 10 W8001299 Remove the mounting bolt from the center of the steering wheel 54 Service Procedures 11 W8001301 Lift the steering wheel from the shaft without turning it Allow the cable and contact reel caution label
32. edures Lower Bunk Restraint Replacement VN 420 610 660 1 Restraint latches 2 Side tether latches 3 Bunk restraint buckles AN DANGER It is critical that any time a vehicle has been involved in an accident the entire safety belt system must be replaced in the vehicle which also includes the sleeper bunk restraints if they were in use at the time of the accident Failure to replace the safety belt sys tem may result in serious injury or death W8002896 AN DANGER When installing safety belt components do not over torque or use high speed pneumatic tools Doing so may cause anchor point failures resulting in the possible failure of the safety belt anchoring system which can cause serious personal injury or death AN DANGER Before working on a vehicle set the parking brakes place the transmission in neutral and block the wheels Failure to do so can result in unexpected vehicle movement and can cause serious personal in jury or death 68 Removal 1 Remove the bunk restraint webbing by releasing the 6 buckles on the re straint 2 Remove one bolt from each of the two restraint latches 1 on the rear wall Group 88 SRS Airbag Safety Belts and Bunk Restraints 3 Remove the bolt from each of the side tether latches 2 on the left and right upper side wall one on each side Note Due to different bunk storage compartment configurations it may be necessary to remove additional cove
33. emental Restraint System SRS Wiring Dia AO ee nene qe RR RP RR PUDE ils 18 Troubleshoot soriana 21 General Work Practices sccccsseccecssseccerssscacoluniesratanieenes 21 Test Resistor Checking is 21 Connecting the Test Resistor oooooooccininccccnnnccccccccccnns 22 Reading Fault LADOS soii 23 MID 232 SID 254 FMI 12 Airbag Control Unit Gamponent FAUNE in N 30 MID 232 SID 1 FMI 6 Igniter Loop Current Hok Shan CUCU arrancar 31 MID 232 SID 1 FMI 5 Igniter Loop Current LEO pon CAGUA asp MID 232 SID 1 FMI 4 3 Igniter Loop Voltage ho plo giro LOW MIGI DRDS UE ERR E MID 232 SID 240 FMI 14 SRS Airbag Crash Data Ord pn ED r Faults Which Do Not Generate a Fault Code SRS Lamp Does Mabe SRS Lamp Does not Light and Not Respond ing Message in Diagnostic Display The SRS Lamp is Lighting but no Fault Code is o juice pa a A E E Routines for a Damaged Faulty Airbag Module Safety Belts and Bunk Restraints Inspection Service Procedures General Work Practices ii After the Airbag Deploys civic Airbag Module Contact Reel Replacement SAS ECU Replacamem ice SRS Wiring Harness Replacement Safety Belt Replacement One Natonal DO raia SUA SAS Safety Belt Replacement One TOO sx QE AR ee NC RD RR RA Lower Bunk Restraint Replacement WYN 420 6106060 lia Lower Bunk Restraint Replacement A
34. er of tests running 0 1 Service and maintenance 1700 08 02 03 Fault codes Fault codes Fault codes 128 Engine ECU identification of control unit FID Parameter Identification irat Bos o f ID Message Identification Description b e Eo ee F Clear single fault code 2436 Brake ECU 2240 Instrument centre mi 444 Vehicle ECU Description identification of parameter value PPID Proprietary Parameter dentification Description Wolvo unique identification of parameter value SID Subsystern Identification Description identification of component PSID Proprietary Subsystern dentification Description volvo unique w cu fib PO PRO SD PSD ocowrences AA A Tal as jective J identification of component mo 232 airbag ECU FMI Failure Mode Identifier PD 1 identification of fault type prio sb h Driver air bag ignition loop PEC Fmi E Current below normal or open circuit number of occurrences f Status active First occurrence himin E Last occurrence himin E Total engine hours 55 35 Modet YNO WINA 778807 start BV CADS Pro Main Menu ll vcaos Pro TestiCalibr 1 Turn the ignition to the ON position 2 With the VCADS Pro tool properly connected and operating select Fault Codes from the Service and Maintenance menu From this screen the VCADS Pro tool can be used
35. erminal opening with tape It is important that the airbag is stored in a secure place Damage to the wiring or connectors in the SRS must never be repaired spliced or partly replaced When a fault is noted and localized in a certain connector or part of the SRS wiring harness the complete wire harness must be replaced Do not turn the steering wheel when the contact reel is secured in the locked position This can damage the contact reel see Airbag Module Contact Reel Replace ment page 52 After the Airbag Deploys After a collision where the SRS airbag has deployed the following components MUST always be replaced e Airbag Module e Steering Wheel e Contact Reel e SRS Electronic Control Unit ECU e SRS Wiring Harness e Safety Belts e Bunk Restraint if in use during collision 51 Group 88 SRS Airbag Safety Belts and Bunk Restraints 8845 03 02 01 Airbag Module Contact Reel Replacement Before starting any service procedure see e General Work Practices page 51 Important Only certified technicians may work on the SRS AN DANGER Before working on a vehicle set the parking brakes place the transmission in neutral and block the wheels Failure to do so can result in unexpected vehicle movement and can cause serious personal in jury or death AN DANGER The airbag module must never be taken apart At tempting to take apart an airbag module which has not been deployed could deploy
36. ety belt National seat 68 7 Nm 50 5 ft lb Safety belt Volvo seat 50 10 Nm 37 7 ft lb Bunk restraints floor roof and rear wall 68 7 Nm 50 5 ft lb Bunk restraints side wall 24 4Nm 212 35 in lb Specifications Group 88 SRS Airbag Safety Belts and Bunk Restraints Tools Special Tools The following tools are required when working on the SRS They are available from Volvo ES BC 585 6960 EJ 9988695 VCADS Pro SRS Test Resistor Diagnostic Tool Tools Group 88 SRS Airbag Safety Belts and Bunk Restraints Tools Other Special Equipment The following tools may be required when working on the SRS Tools beginning with a J number are available from Kent Moore at 1 800 328 6657 J 39200 J 42449 1 J 42449 2 Fluke 87 Terminal Probe Terminal Probe Digital Multimeter J 38500 1 J 38500 2 J 38500 60A J 38500 2000 Power Data Cable Diagnostic Adaptor Cable Pro link 9000 and for Pro link for Pro link Volvo Data Cartridge Group 88 SRS Airbag Safety Belts and Bunk Restraints Design and Function Design and Function Safety Belts and Bunk Restraints The seat safety belts and bunk restraints are the principal safety device used in the vehicle The safety belts bunk restraints must be worn at all times if the vehicle is in motion even if the vehicle is equipped with a SRS sys tem airbag Instructions on proper safety belt bunk restraint use can be found in the operator s manual Safety belt assem
37. fraying or extreme wear in the web bing Cuts frays or excessive wear indicate the need for replacement of the safety belt system KOMFORT LATCH TO RELEASE PULL DOWN ON SHOULDER STRAP W8001405 The D loop web guide is an area where almost constant movement of the safety belt webbing occurs because of the relative movement be tween the seat and the cab Because of this constant movement this is an area where wear will often occur The webbing must be closely examined to determine if there are any cuts frays or extreme wear in the webbing Cuts frays or excessive wear indicate the need for replacement of the safety belt system 47 Group 88 SRS Airbag Safety Belts and Bunk Restraints Troubleshooting 3 6 Check that the D loop web guide is rotating properly If the guide is not ro RQ tating properly the webbing will pull at the wrong angle through the guide ac celerating wear KOMFORT LATCH TO RELEASE PULL DOWN ON SHOULDER STRAP A W8001403 Check the Komfort Latch for cracks or E possible damage and that it works _ properly W8001401 The retractor web storage device is 5 mounted on the B pillar of the vehi cle The retractor is the heart of the safety belt system and can be dam aged if abused even unintentionally Check the retractor web storage de vice operation to ensure that it is not locked and that it spools out and re tracts the webbing properly W8001404 Check the buc
38. from two deceleration sensors and controlling the deployment of the airbag module e memory function which stores information concern ing possible faults in the system even after the voltage has been broken this facilitates fault trac ing Control Unit Function If the control unit determines the force and duration of a collision is sufficient to activate the system it activates the electrical igniter which activates the gas generator filling the airbag with a harmless gas and deploying the bag The impulses sent by the control unit to deploy the airbag module are in the form of AC voltage signals Ca pacitors in the airbag module connector allow these pulsating signals to pass through but block DC voltage signals and static discharge For the control unit to function correctly it is important that it is securely attached to the truck cab otherwise it does not register the time from the beginning of the colli sion but instead from the moment when the control unit itself begins to decelerate Standby Mode The control unit contains a standby power unit This stores sufficient power so that the system functions even if voltage from the battery is broken or too low under 8 5 volts The SRS indicator on the dash will illuminate at 7 volts The power is stored for a few seconds after the voltage has been broken The power is sufficient to trigger the igniter for less than 1 second in the event of a collision where the batte
39. hicle which also includes the sleeper bunk restraints if they were in use at the time of the accident Failure to replace the safety belt sys tem may result in serious injury or death AN DANGER Before working on a vehicle set the parking brakes place the transmission in neutral and block the wheels Failure to do so can result in unexpected vehicle movement and can cause serious personal in jury or death AN DANGER When installing safety belt components do not over torque or use high speed pneumatic tools Doing so May cause anchor point failures resulting in the possible failure of the safety belt anchoring system which can cause serious personal injury or death Removal 1 Remove the bunk restraint 1 by re leasing the 6 buckles 2 Remove the bolts securing the re straint latches 2 on the rear wall 3 If the vehicle is equipped with an up per bunk remove the support cover that covers the side tether brackets 4 Remove the bolts securing the left and right side tether brackets 3 or 4 5 Remove the bolt head covers and bolts securing the lower restraint buckle 5 Service Procedures Installation 6 Install the replacement lower restraint 68 7 Nm buckle Torque the bolts to 68 7 Nm 50 5 ft lb 50 5 ft lb Install the bolt head cov ers 7 Install the replacement left and right 24 4Nm side tether brackets Torque the bolts 212 35 in to 24 4 Nm 212 35 in lb Inst
40. illuminated the SRS should be repaired as soon as possible The fault codes can be accessed by using the graphic display in the instrument cluster or with electronic diag nostic tools The diagnostic socket is located below the dash on the left hand side For more information refer to Troubleshooting SRS Wiring Harness The SRS wiring harness is a specially designed and manufactured cable that connects to the cab main wiring harness at one end with wires for power to the ECU in dicator lamp and data link The other end connects to SRS control unit From the control unit wires are fed to the contact reel for the airbag module Located under the truck dash the harness is orange in color for easy identification The SRS wire harness must never be repaired or spliced With a faulty harness breakage or short circuit ing it must be replaced with a new harness Otherwise the system may not function correctly See SRS Wiring Harness Replacement page 59 Diagnostic socket Design and Function Group 88 SRS Airbag Safety Belts and Bunk Restraints Design and Function Supplemental Restraint System SRS Wiring Diagram Wiring Diagram vehicles built prior to 3 99 FV oa Airbag Module BL 721 9 GN 400 SAE J1587 data link 12 YL 401 SAE J1587 data link GND via mounting screws W8002903 Note Numbers in parentheses are circuit numbers printed on the wire insula
41. ing personal injury or death Unless otherwise stated in the instructions the test resis tor 9988695 should be connected to the airbag module connector when the airbag module has been removed T8006845 If the SRS is connected to supply voltage when an Connect the test resistor to the airbag module con airbag module has been removed and the test resistor nector is not connected a fault will be registered which must later be erased 22 Group 88 SRS Airbag Safety Belts and Bunk Restraints Reading Fault Codes Troubleshooting Fault codes generated by the SRS control unit are displayed read and cleared differently depending on the type of instrument cluster and electrical system that is installed in the vehicle Vehicles built prior to 3 99 used a different in strument cluster and electrical system than vehicles built after that date For fault code information with each type of system see Reading Fault Codes vehicles built before 3 99 page 24 or Reading Fault Codes vehicles built from 3 99 page 27 Active Faults When a fault code is generated there is a risk that the SRS system will not function The driver receives a warning that something is faulty if the SRS indicator lamp icon comes on The indicator stays active until the active fault condition is repaired and the fault code cleared Inactive Faults An active fault becomes inactive when the fault condition is repaired With an ina
42. ional ground cables were connected to the battery such as engine ECU satellite system etc Other wise electronic modules may be damaged when additional grounds are connected disconnected with out the main battery ground connected Always connect the main battery ground first T8006863 38 Group 88 SRS Airbag Safety Belts and Bunk Restraints MID 232 SID 1 FMI 4 3 Igniter Loop Voltage Shorted Low High Airbag Module Short Circuiting to Volt age or to Ground Conditions for fault code The control unit checks if the signal is continuously high or continuously low 0 V in the cable circuit which means short circuiting to voltage or to ground If this is the case fault code MID 232 SID 1 FMI 4 Driver Igniter Loop Voltage Shorted Low or MID 232 SID 1 FMI 3 Driver Igniter Loop Voltage Shorted High will be gener ated Fault symptoms No fault symptoms other than the SRS indicator illumi nates There is a risk that the SRS will not work with this fault code Cause of fault Short circuiting to voltage or ground in the ignition cable or the connector between the airbag module and the SRS ECU Alternatively short circuiting to voltage or ground in the airbag module resistance too low in the igniter or in the contact reel Action To be able to find the cause of the fault troubleshoot according to the following procedures Follow the proce dures carefully Do not skip over an item before the cause of the
43. is a risk that the SRS will not work if this fault code is generated Cause of fault Internal fault in the control unit Action Replace the control unit ECU See SRS ECU Re placement page 57 for replacement instructions 30 Troubleshooting T8006850 Group 88 SRS Airbag Safety Belts and Bunk Restraints Troubleshooting MID 232 SID 1 FMI 6 Igniter Loop Current High Short Circuit Airbag Module Short Circuit AN DANGER NEVER use an ohmmeter or other live measuring in strument to measure the resistance of the airbag module This practice could cause the airbag to de ploy causing serious injury or death T8006872 Airbag module Condition for fault code If the resistance is too low in the airbag module or in the cable circuit short circuiting between the cables fault code MID 232 SID1 FMI 6 is stored Fault symptoms No fault symptoms other than the SRS indicator There is a risk that the SRS will not work with this fault code Cause of fault Short circuiting in the ignition cable or the connector between the airbag module and the control unit Alterna tively short circuiting in the airbag module too low a resistance in the igniter or in the contact reel Action To be able to find the cause of the fault troubleshoot according to the following procedures Follow the proce dures carefully Do not skip over an item before the cause of the fault is localized See Routine
44. ise personal injury may result due to possible deployment of the airbag If there are other ground cables connected to the bat tery such as engine ECU satellite system etc connect the battery ground cable first then connect those grounds Electronic modules may be damaged when additional grounds are connected disconnected without the main battery ground connected W8001306 Remove the locking screw from the contact reel before installing the steer ing wheel Align the 2 studs on the contact reel and feed the module con nector through hole in the center of the steering wheel Center the steer ing wheel and install 19 Install a new bolt in the center of the steering wheel and torque to 85 15 Nm 63 11 ft lb Install the contact reel locking screw with the caution label attached into the steer ing wheel 85 15 Nm 63 11 ft lb Note Check to be sure no metal parti cles are around the airbag connector pins 20 Connect the electrical connector from the contact reel to the airbag module Install the airbag to the steering wheel Secure the airbag with existing bolts in the steering wheel Access these bolts from the 2 holes in the bottom of the steering wheel Torque the bolts to 10 1 5 Nm 89 13 in lb 10 1 5 Nm 89 13 in lb 56 Turn the ignition switch to the ON posi tion Make sure nobody is in the cab Close the cab windows and doors but leave the passenger side window open
45. k test lead Then measure from terminal 2 One or two mea Short circuiting Change the cable using the meter s red test lead wso01343 SUrements give a harness to a known power source with value of O 2 the black test lead 41 Group 88 SRS Airbag Safety Belts and Bunk Restraints Troubleshooting After Fault Tracing Repair Con necting the Battery When all the components in the cab have been rein stalled turn the ignition switch to the ON position and reconnect the battery heeding the warnings below Note Leave the passenger side window open because the power locks may lock the doors when the battery is 78006863 reconnected Personal injury risk Make sure that no one is inside the cab and that the ignition switch is in the ON posi tion when connecting the battery and that the cab doors and driver side window are closed Otherwise personal injury may result due to possible deployment of the airbag Connect the negative battery lead then connect any additional ground cables back to the battery if addi tional ground cables were connected to the battery such as engine ECU satellite system etc Other wise electronic modules may be damaged when additional grounds are connected disconnected with out the main battery ground connected Always connect the main battery ground first 42 Group 88 SRS Airbag Safety Belts and Bunk Restraints MID 232 SID 240 FMI 14 SRS Airbag Crash Data Stored
46. kle by inserting the latch and verify proper operation Determine if the latch plate is worn or deformed Check the buckle and latch casing for cracks or breakage 48 Group 88 SRS Airbag Safety Belts and Bunk Restraints SA W8001387 If tethers are being used to anchor the safety belts to the floor or bunk walls make sure they are properly attached to the seat Tethers must also be in spected for web wear and proper tightness of mounting hardware Troubleshooting 8 All hardware for safety belt mounting points should be evaluated for corro sion All attachment points of the system should be checked for tight ness of mounting hardware 9 Check web in areas exposed to ultravi olet rays from the sun or extreme dust or dirt If the original color of the web in these areas is extremely faded the physical strength of this web may have deteriorated If this condition exists re place the system 10 Check the stitching of the bunk re straint cross hatch webbing for proper integrity Replace the bunk restraint if needed 49 50 Group 88 SRS Airbag Safety Belts and Bunk Restraints Service Procedures Service Procedures General Work Practices The ignition key should always be in the OFF position before beginning any repairs unless otherwise stated When an airbag module has been removed make sure that no particles metal filings etc can enter the module contact pins igniter so cover the t
47. lay will display fault codes Faults may be displayed as SAE J1587 text mes sages or numeric codes To check for fault codes in the SRS system 1 2 28 Turn the key to the ON position Use the Esc button to access the main menu structure Select System Diagnostic Fault Diagnostic Air Bag If there is a fault code or codes the following is shown for example Air bag Controller 1 Component failure Active gt 1 MM Line 1 Identification of ECU Line 2 Identification of parameter component Line 3 Identification of fault type Y 1 shows how many times the fault has been registered since the last resetting If there is no in formation available for how many times the fault code has been registered only Active is shown the fault remains Or alternatively Inactive is shown the fault was there previously The arrow in the lower right hand corner is shown if there is more than one fault code To switch to numerical format press the J or Select button Press the Up or Down arrow buttons to check for any additional fault codes Record any fault codes for future reference To exit press the Esc button as needed to return to the main menu Troubleshooting Clearing Fault Codes with the Graphic Display Note Any faults must be inactive before they can be cleared All system faults will be cleared not just SRS faults A 2
48. lead to terminal 10 Measure resistance across ter 2 Possible bad ECU Check the ECU minal 2 on the ignition cable Wanted go to step 5 connector to terminal 11 at the ECU connector Use tool J 42449 1 to connect a test lead to terminal 11 37 Group 88 SRS Airbag Safety Belts and Bunk Restraints Troubleshooting Step 5 Ignition OFF e Remove SRS ECU Measure the resistance between terminals 10 and Approx 45 50 Short circuiting in the Recheck the ignition 11 on the ECU connector Use tool J 42449 2 to kQ ignition cable contact cable contact reel connect test leads to terminals 10 and 11 reel or airbag module and airbag module Anything out Bad ECU Replace ECU side 45 50 kQ After Fault Tracing Repair Con necting the Battery When all the components in the cab have been rein stalled turn the ignition switch to the ON position and reconnect the battery heeding the warnings below Note Leave the passenger side window open because the power locks may lock the doors when the battery is reconnected Personal injury risk Make sure that no one is inside the cab and that the ignition switch is in the ON posi tion when connecting the battery and that the cab doors and driver side window are closed Otherwise personal injury may result due to possible deployment of the airbag Connect the negative battery lead then connect any additional ground cables back to the battery if addi t
49. les built before 3 99 only 2 INFO indicator and SRS icon are always on with no fault code vehicles built after 3 99 only Cause of Fault Open circuit on the ECU power supply wire Blown SRS ECU fuse in fuse panel Open circuit on the SRS indicator lamp wire vehi cles built before 3 99 only Improper ground connection on SRS ECU Note If power has been lost to the ECU the Pro link tool will display NOT RESPONDING in the SRS Diag nostic menu 2The SRS ECU will operate at up to 36 volts but other systems in the vehicle should never be exposed to voltages that high The instrument cluster for example is rated at a maximum operating voltage of 18V 45 Group 88 SRS Airbag Safety Belts and Bunk Restraints Routines for a Damaged Faulty Airbag Module Handling An airbag module that has not deployed must not be detonated or deployed neither in position in the truck nor when removed from the truck The module and the control unit must be returned to Volvo Additionally if there is any damage to the engine tunnel the control unit must always be returned When removing the unit refer to Airbag Mod ule Contact Reel Replacement page 52 Storage and Transport During transport the airbag module should be handled in accordance with national regulations for transport of pyrotechnic material The airbag module and control unit should be sent back to Volvo Truck Corporation Att TMA Haverikommissionen Dept
50. negative battery lead and torque to 24 27 Nm 18 20 ft lb W8001461 Important Route harness exactly as shown Use tie straps exactly where shown 17 View faults to see if any fault codes appear There should be no active fault codes for the SRS system If any active fault codes are present they need to be repaired AN CAUTION Failure to follow the routing shown when installing an SRS harness can result in damage to the wiring har ness and the SRS may not function If equipped with tilt steering adjust the steering column to the upright posi 18 tion Route the SRS harness along the Install the lower steering column cover steering column wiring and connect the harness connector to the contact reel Secure the harness using 3 tie straps along the steering column as shown Install 3 tie straps on the bracket below the steering column Secure the SRS harness to the main cab harness between the steering col umn and SRS ECU Important If equipped with tilt steer ing move the steering column to check for pulling or pinching of the SRS or main cab harness at the steer ing column 62 Align the weld studs through the holes into the bottom of the panel Install the plastic rivets to secure the top of the panel Group 88 SRS Airbag Safety Belts and Bunk Restraints 19 W8001302 Install the rear steering column cover Torque the 3 bolts to 5 0 8 Nm 44 7 in lb Position the stalk switches rubber gr
51. nit ing through static electricity or through careless handling of current C2 prevents the igniter from activating due to unintentional high frequency disturbances Resistance cannot be measured on the circuit as the ca pacitor blocks measurement There is a service hole 1 in the connector to facilitate fault tracing Testing the Cable from the Airbag Module Connector e Place two small steel pins for example needles max diameter 1 mm in the service hole 1 and in the connector pin 2 nearest the service hole and perform the measurements on these Normal resis tance is 45 50 kQ Contact Reel The contact reel completes the connection between the wire harness and the airbag module on the steering wheel The contact reel is made up of a coiled ribbon cable which makes it possible for the airbag module con nector to follow the rotation of the steering wheel The other cable provides the connection to the control unit There are two rings on the contact reel for the horn slip contacts Avoid turning the contact reel more than 3 turns either direction from the centered position This can damage the contact reel 14 Design and Function Cy Lo axo T8006860 Airbag module connector T8006881 Contact reel Group 88 SRS Airbag Safety Belts and Bunk Restraints Design and Function SRS Indicators vehicles built prior to 3 99 SRS indicator lamp and graphic display SRS Indicator Lamp prior
52. ollowing A or represents the or der in which the fault was received 5 SAE J1587 SID fault code 6 SAE J1587 FMI fault code W8001324 EB ON a Record all codes displayed To display the next stored fault code press the Down button After all faults have been repaired the display will change to No Active Codes This means that the fault has become inactive and can be cleared Group 88 SRS Airbag Safety Belts and Bunk Restraints Troubleshooting Reading Fault Codes with the Graphic Display 5 When the first message appears the Set button can be pressed to toggle the display between the text description and the received data MID PID SID or FMI a If the condition that caused the currently dis played fault still exists the cluster will display ACTIVE Mm gt 0 AIRBAG q UR AIRBAG IGN LOOP 5 CURRENT LO GPEN L N ACTIVE W8001313 Graphic Display pe W8001346 b If the condition that caused the currently dis 1 Turn the ignition ON played fault has been repaired the cluster display will not change until the diagnostics 2 Press the Mode button on the instrument cluster un aaa exited and eed again i the fault til DIAGNOSTIC MENU is displayed in the graphic has been successfully repaired it will display display INACTIVE when the diagnostic messages are 3 Use the Up and Down buttons to display DIAGNOS displayed again TIC MESSAGES S 4 When DIAGNOSTIC MESSAGES is displ
53. ommets over the front and rear covers Install the plastic clips in the bottom of the covers 20 Install the lower dash panel center and right sections Torque the 8 bolts to 3 5 0 5 Nm 31 4 5 in lb Also in stall the 4 plastic nuts Make certain to pull the mat back and align the weld studs through the holes Insert A C ductwork through the center panel 21 Install the right front grab handle with 2 bolts Torque to 24 4 Nm 18 3 in lb Install the bolt cap in the trim panel 22 Install the lower left dash trim panel with 3 bolts and 1 plastic nut at the bottom weld stud Make certain to in sert the A C ductwork and diagnostic connector 23 Install the left front grab handle with 2 bolts Torque to 24 4 Nm 18 3 in lb Install the bolt cap in the trim panel Service Procedures 8841 03 02 01 Safety Belt Replacement One National Seat AN DANGER It is critical that any time a vehicle has been involved in an accident the entire safety belt system must be replaced in the vehicle which also includes the sleeper bunk restraints if they were in use at the time of the accident Failure to replace the safety belt sys tem may result in serious injury or death AN DANGER Before working on a vehicle set the parking brakes place the transmission in neutral and block the wheels Failure to do so can result in unexpected vehicle movement and can cause serious personal in jury or death AN
54. r panels to access the side tether bracket bolts 4 Remove one bolt from each of the two bunk restraint buckles 3 These buck les are mounted to the floor in front of the bunk assembly on the left and right side Installation 5 Install the two bunk restraint buckles 3 mounted to the floor in front of the bunk assembly left and right side In stall the bolt and position the buckles to the correct position Torque each buckle assembly to 68 7 Nm 50 5 ft lb 6 Install one bolt in each of the two side tether latches 2 one on each side wall Align to the correct position and torque latch assembly to 24 4 Nm 212 35 in lb 7 Install one bolt for each of the two re straint latches on the rear wall 1 Align latch to the correct position and torque to 68 7 Nm 50 5 ft lb In stall the bunk restraint webbing 68 7 Nm 50 5 ft lb 24 4 Nm 212 35 in lb Service Procedures 69 Service Procedures Lower Bunk Restraint Replacement VN 770 Group 88 SRS Airbag Safety Belts and Bunk Restraints 8844 03 02 01 x Sues x 5 vo 25 E 5 o gt E E gt FRA E aO E sS558 TREE Too o a nn DU o aX 2503 oO Selos DESSE E 2 2 E DD OU Aaron a TON OL Group 88 SRS Airbag Safety Belts and Bunk Restraints AN DANGER It is critical that any time a vehicle has been involved in an accident the entire safety belt system must be replaced in the ve
55. ring that 10 seconds the SRS self diagnosis is being carried out After the self diagnosis is complete the con trol unit reduces the voltage to the indicating circuit to approx 0 8 2 0 V and the lamp goes out When the lamp is on there is a voltage of approx 12 V on the ca ble With either a too low or too high battery voltage lt 8 5 volts or gt 36 volts see note the indicator lamp SRS lamp will light up at the same time the control unit goes into standby mode which means that the control unit will try to provide full function As soon as the voltage is cor rect the indicator lamp goes out and the system functions normally but with for example undervoltage it will take a longer time to charge up the energy reserve There is no fault code stored for incorrect battery voltage The SRS indicator lamp can be illuminated even if the control unit is faulty or with a breakage in the indicator lamp wire between the control unit and instrument clus ter Conditions for Fault vehicles built after 3 99 The INFO lamp and all other telltales should illuminate 3 5 seconds when the ignition key is turned to ON to verify that the telltale bulos operate With no power to SRS ECU the INFO lamp will illuminate and and the SRS icon will appear on the graphic display When ac cessed the graphic display will read AIR BAG MID 232 NOT RESPONDING Fault Symptom 1 The SRS lamp is always on with no fault code vehi c
56. rt circuiting in Replace the ca the ignition cable ble harness W8001343 33 Group 88 SRS Airbag Safety Belts and Bunk Restraints Troubleshooting Step 5 Ignition OFF e Remove SRS ECU Measure the resistance between pins 10 and 11 Approx 45 50 Short circuiting in the Recheck the ignition on the ECU connector Use tool J 42449 2 to con KQ ignition cable contact cable contact reel nect test leads to pins 10 and 11 reel or airbag module and test resistor After a recheck of the sys tem shows the other components are ok replace the airbag module Anything out Bad ECU Replace ECU side 45 50 kQ After Fault Tracing Repair Con necting the Battery When all the components in the cab have been rein stalled turn the ignition switch to the ON position and reconnect the battery heeding the warnings below Note Leave the passenger side window open because the power locks may lock the doors when the battery is reconnected Personal injury risk Make sure that no one is inside the cab and that the ignition switch is in the ON posi tion when connecting the battery and that the cab doors and driver side window are closed Otherwise personal injury may result due to possible deployment of the airbag Connect the negative battery lead then connect any additional ground cables back to the battery if addi tional ground cables were connected to the battery such as engine ECU satellite s
57. ry function has been broken The control unit will also go into standby mode if the voltage from the battery is too high over 36 volts see note the control unit will still try to operate to full capacity As soon as the voltage is correct the SRS indi cators will go out and the system will function normally SRS Components Design and Function SRS control unit T8006850 The SRS ECU will operate at up to 36 volts but other systems in the vehicle should never be exposed to voltages that high 11 Group 88 SRS Airbag Safety Belts and Bunk Restraints Design and Function Control Unit Ground Connection The control unit s ground connection is a direct ground to the SRS mounting plate to which the SRS ECU is mounted with 3 bolts One of the 3 bolts is attached to a ground strap which case grounds the ECU to the plate There should be no particles of dirt between the control unit and the mounting plate The mounting plate is grounded to the cab body When replacing or installing a new SRS control unit be sure the unit is mounted properly as shown in SRS ECU Replacement page 57 Control Unit Connector Avoid touching any of the control unit connector pins when the connector has been disconnected Risk for electrostatic discharge which can damage the control unit The control unit connector is located on the SRS wiring ASS 2 harness It is a 90 angled connector that connects the W8001322 wiring harness
58. s and removing the rivets 60 Service Procedures Ze LD NY W8001463 Contact reel connector Disconnect the SRS harness at the contact reel connector Cut the tie straps running down the steering col umn bracket 3 places being careful not to cut any wires in the main har ness Cut the 3 tie straps from the lower bracket Pull the SRS harness from the main harness on the steering column Cut any tie straps fastening the SRS harness to the main cab har ness Separate the SRS harness from the main cab harness between the steering column and SRS ECU Group 88 SRS Airbag Safety Belts and Bunk Restraints 10 W8001465 Risk of damage to the control unit from electro static discharge ESD To avoid ESD damage do not touch the control unit contact pins and wear an anti static wrist strap grounded to the nearest electrical ground Cut and remove the tie straps around the SRS ECU and disconnect the SRS ECU electrical connector Push in on the tab holding the connector locking arm to release the connector Remove the SRS harness Note In some early production vehi cles built before May 1997 the cover must be removed from the SRS ECU to disconnect the connector If the connector cannot be accessed with the cover on remove the cover by re moving the 2 mounting bolts Service Procedures Installation W8001322 1 Locking tab 2 Locking arm shown in unlocked position Connect the
59. s flows out through two holes in the back of the bag These holes are large enough to let the airbag collapse slowly gently catching the driver The control unit also contains a standby power unit which can supply the system with power for a short time should the normal power supply be broken W8001291 Types of Collision The Volvo SRS airbag provides increased protection in frontal collisions where the truck collides with a fixed or heavy object with enough force for the sensors to acti vate the gas generator which deploys the bag The damage to the truck is not always proportional to whether the SRS airbag deploys or not The SRS airbag is not designed to be activated when the e collision is from the sides e collision is from the rear e accident is a roll over e collision is at low speed or against soft objects such as bushes snow drifts etc This means that the safety belt must always be used The SRS airbag only provides supplemental protection Group 88 SRS Airbag Safety Belts and Bunk Restraints Supplemental Restraint System SRS Control Unit ECU The Control Unit Contains e two deceleration piezo electrical sensors which sense the deceleration collision They detect a com bination of the magnitude of the G forces and the duration In order for the control unit to activate the system it requires both a high G force and a pro longed deceleration collision e microprocessors for evaluating the signals
60. s for a Damaged Faulty Airbag Module page 46 concerning the handling of a damaged airbag module 31 Group 88 SRS Airbag Safety Belts and Bunk Restraints Troubleshooting Fault Code MID 232 SID 1 FMI 6 Driver Side Igniter Loop Current High Short Circuit Before disconnecting or connecting the airbag mod ule turn the ignition key OFF and remove the battery ground cable If there are other ground cables connected to the bat tery such as engine ECU satellite system etc disconnect those grounds first then remove the bat tery ground cable Electronic modules may be damaged when additional grounds are con nected disconnected without the main battery ground connected Always disconnect the main battery ground last Step 1 Ignition OFF Disconnect the negative lead from the battery Remove the airbag module AN DANGER Remove the airbag module and install the test resistor when troubleshooting the wiring harness for the SRS system Failure to do so could cause the airbag to de ploy during troubleshooting causing serious personal injury or death To avoid injury the battery must not be connected when the airbag module is being removed or installed If the battery is connected deployment of the airbag may occur possibly causing personal injury or death Check resistance of test resistor 9988695 see Test Resistor Checking page 21 If resistance is ok connect the resistor to the connector
61. ted discon nected without the main battery ground being connected Always disconnect the main battery ground last Turn the ignition switch OFF and dis connect battery ground cables to any ECUs that may be connected to the battery such as engine ECU satellite system etc Then remove the battery ground cable Service Procedures 2 Remove the left front grab handle by removing the bolt cap in the trim panel then removing the upper and lower bolts 3 Remove the 3 torx bolts and plastic nut from the lower dash trim panel to the left of the steering column Re move the diagnostic connector and vent hose from the panel then remove the panel 4 Remove the right front grab handle by removing the bolt cap in the trim panel then removing the upper and lower bolts W8001464 To remove the right and center lower dash panels remove the 8 bolts along the top of both panels and the 3 plas tic nuts on the bottom of the right panel and the 1 plastic nut from the center lower panel 59 Group 88 SRS Airbag Safety Belts and Bunk Restraints W8001302 Remove the 2 clips at the bottom of the steering column cover W8001303 Remove the rear steering column cover by removing the 3 torx bolts from the cover and sliding the rubber grommets off of the cover at the stalk switches 8 Remove the lower section of the steer ing column cover by pushing the centers through on the plastic rivet
62. the airbag causing serious injury or death The white powder residue from a deployed airbag can be an irritant to skin and tissue To avoid injury wear gloves and a dust mask when handling a deployed module and avoid getting this white powder in eyes or on skin If skin irritation occurs immediately flush the skin with water Seek medical attention if irritation continues Removal 1 Align the vehicle wheels straight and center the steering wheel to prevent damage to the new contact reel due to the limited number of turns available 52 Service Procedures T8006862 If there are other ground cables connected to the bat tery such as engine ECU satellite system etc disconnect those grounds first then remove the bat tery ground cable Electronic modules may be damaged when additional grounds are con nected disconnected without the main battery ground connected Always disconnect the main battery ground last Turn the ignition switch OFF and dis connect the battery 3 If the vehicle has a locking steering column turn the ignition switch to the ON position to unlock the steering wheel W8001304 Loosen the two mounting bolts for the airbag module through the access holes on the underneath side of the steering wheel until the airbag module releases Group 88 SRS Airbag Safety Belts and Bunk Restraints Service Procedures W8001298 Disconnect the airbag module electri cal connector and remov
63. the up per bunk bottom trim panel to allow access to the restraint buckle mounts Remove the lower screw securing the fold up latch release strap 76 Service Procedures 5 Gently fold the trim panel forward and remove the restraint buckle 4 mount ing screws and remove the restraint buckles Installation 6 Install the replacement restraint buck les Torque the bolts to 12 2 Nm 106 17 in lb 7 Install the lower screw securing the re placement latch release strap Secure the upper bunk bottom trim panel 8 Install the replacement left and right side tether brackets Torque the bolts to 24 4 Nm 212 35 in lb 9 Install the replacement latches on the rear wall Torque the nuts to 68 7 Nm 50 5 ft lb 10 Install the replacement bunk restraint Check for proper fit and adjust as needed Feedback One of our objectives is that workshop personnel should have access to correct and appropriate service manuals where it concerns fault tracing repairs and maintenance of Volvo trucks In order to maintain the high standards of our literature your opinions and experience when using this manual would be greatly appreciated If you have any comments or suggestions make a copy of this page write down your comments and send them to us either via telefax or mailing directly to the address listed below To From Volvo Trucks North America Inc Dept 516 Service Publications 7825 Na
64. tion Group 88 SRS Airbag Safety Belts and Bunk Restraints Design and Function Wiring Diagram vehicles built from 3 99 HV pat 10 OR O Contact reel O Airbag BL 721 Module SAE J1587 data link 91 GN 400 12 YL 401 SAE J1587 data link GND via mounting screws W8002904 Note Numbers in parentheses are circuit numbers printed on the wire insulation 20 Group 88 SRS Airbag Safety Belts and Bunk Restraints Troubleshooting Troubleshooting General Work Practices Unless otherwise stated the ignition key should be in the OFF position during troubleshooting Damaged wires or connectors in the SRS system must never be repaired spliced or partially replaced When a fault is noted and localized to a certain connector or wire harness the complete harness must be changed Test Resistor Checking When fault tracing and checking the SRS system it is important that there is no fault on the test resistor 9988695 A defective test resistor will cause the diag nostic system to give false readings and will make fault tracing and checking more difficult To be sure that there is no fault in the test resistor it should always be checked using an ohmmeter before it is used Removing the Short Circuit Element Before checking resistance remove the short circuit ele ment between the test resistor pins as follows 1 Wear safety glasses during this procedure 2 Pry
65. tional Service Road P O Box 26115 Greensboro NC 27402 6115 USA Fax 336 393 3170 Comments proposals 3741 03 02 01 8841 03 02 01 8844 03 02 01 8844 03 02 02 8845 03 02 01 8847 03 02 01 Operation Numbers SRS Wiring Harness Replacement e 59 Safety Belt Replacement One 63 65 Lower Bunk Restraint Replacement 68 70 Upper Bunk Restraint Replacement aoa oa a a 12 75 Airbag Module Contact Reel Replacement oa a o a a a a 52 SRO EGU Replacement o so act aropin aop a oh CRE AA CAE RE ew 57 VOLVO Volvo Trucks North America Inc P O Box 26115 Greensboro NC 27402 6115 Volvo Trucks Canada Ltd 6490 Vipond Drive Mississauga Ontario L5T 1W8 http Awww volvotrucks volvo com PV776 TSP144851 1000 05 2001 Volvo Trucks North America Inc 2001
66. to retrieve or clear fault codes by entering the correct prompts 3 Before clearing the inactive fault codes check for fault codes in other vehicle ECUs and record for later reference When clearing fault codes the Clear all fault codes request must be selected When this command is entered all inactive fault codes not just SRS fault codes will be cleared W8002905 Note Do not clear fault code MID 232 SID 240 FMI 14 This code is present after an SRS ECU has detected a crash The SRS ECU airbag module contact reel steer ing wheel and safety belts must be replaced after a crash If the bunk restraint was in use it must also be re placed Note Do not clear fault code MID 232 SID 254 FMI 12 Replace the SRS ECU see SRS ECU Replacement page 57 29 Group 88 SRS Airbag Safety Belts and Bunk Restraints MID 232 SID 254 FMI 12 Airbag Control Unit Compo nent Failure Fault in the Control Unit Conditions for fault code The control unit contains in addition to the sensors a reserve power unit a power amplifier for triggering the igniter in the airbag module functions for continuous monitoring and storing of generated faults both internally in the control unit as well as the remainder of the system If the self diagnostic system registers a fault in one of the internal functions fault code MID 232 SID 254 FMI 12 is generated Fault symptoms No symptoms apart from the SRS indicator s There
67. to the SRS control unit It is equipped 1 Locking tab with a locking arm 2 Locking arm shown in unlocked position To lock move arm in direction of arrow to the Before disconnecting the ECU connector wait at least 3 seconds after voltage is removed to make certain power has discharged completely locking tab To disconnect the wiring harness from the control unit the locking arm 2 must be pulled back from its locked position at the locking tab 1 and pushed back to the unlocked position shown in the illustration This also pushes the connector out of the socket on the control unit Then pull gently on the connector until it comes completely out of the control unit To reconnect the wiring harness carefully insert the con nector into the control unit and push the locking arm back over the connector towards the locking tab 1 The latch will lock in place 12 Group 88 SRS Airbag Safety Belts and Bunk Restraints Airbag Module The airbag module should be replaced every 10 years to maintain reliability See Airbag Module Contact Reel Replacement page 52 AN DANGER Personal injury risk Always store a non deployed airbag module with the metal underneath side down and in a place where it will not be handled carelessly This is to reduce the chances of the airbag being ejected from its storage position if accidentally de ployed which could cause serious personal injury or death Airbag Module Function
68. us injury or death See the Operator s Manual for correct safety belt usage If it is determined that the safety belts bunk restraints need to be replaced only Volvo replacement parts should be used Additionally if one part of the safety belt or bunk restraint is found to need replacement the entire assembly must be replaced See Service Procedures for replacement instructions W8002901 Bunk Restraint Group 88 SRS Airbag Safety Belts and Bunk Restraints Design and Function Supplemental Restraint System SRS System Overview The SRS is supplemental protection for use together with the safety belt The SRS is designed to reduce the risk of injury to the driver s face and upper body Together with the safety belt the bag helps to prevent the driver from being thrown against the steering wheel windshield and other hard surfaces in the cab How SRS Works The system consists of an inflatable bag mounted in the center of the steering wheel and a control unit mounted on the bulkhead inside the cab A chemical based gas generator attached to the rear of the bag inflates the bag in the event of a collision Sensors in the control unit detect rapid deceleration If the control unit detects a sufficiently violent deceleration collision the system is activated The gas generator activates and fills the bag with a harmless gas within a few hundredths of a second During a collision after the bag has been filled the ga
69. where the airbag module was removed Ignition ON Ignition position Re connect the battery negative lead Read the fault codes The same fault code MID 232 SID1 FMI 6 is displayed 32 No active fault code Short circuiting in the airbag Change the airbag module module There is no fault in the airbag module con tinue with step 2 Group 88 SRS Airbag Safety Belts and Bunk Restraints Troubleshooting Step 2 e Ignition OFF Remove test resistor 9988695 Measure the resistance Approx 45 50 Bad test resistor Check test resistor If across 1 and 2 on the kQ bad replace and re airbag module connec peat check tor Short circuiting in the Disconnect the igni ignition cable contact tion cable from the reel or ECU contact reel and re peat the check at the airbag module con nector If O Q replace the contact reel If open circuit continue with step 3 W8001334 Disconnect the ignition cable 45 50 kQ Bad contact reel Change the con from the contact reel and tact reel measure resistance between ter minals 1 and 2 on the ignition cable connector Short circuiting in Check the cable the ignition cable harness go to or ECU step 4 W8001343 Disconnect the ignition cable OL or OC Ignition cable is Check ECU go from the ECU and measure re open circuit ok ECU possibly to step 5 sistance between terminals 1 and bad 2 on the ignition cable connector ae e g Sho
70. ystem etc Other wise electronic modules may be damaged when additional grounds are connected disconnected with out the main battery ground connected Always connect the main battery ground first T8006863 34 Group 88 SRS Airbag Safety Belts and Bunk Restraints MID 232 SID 1 FMI 5 Igniter Loop Current Low Open Circuit Airbag Module Breakage AN DANGER NEVER use an ohmmeter or other live measuring in strument to measure the resistance of the airbag module This practice could cause the airbag to de ploy causing serious injury or death Conditions for fault code If the resistance is too low in the airbag module or in the cable circuit breakage in the cable fault code MID 232 SID 1 FMI 5 is stored Fault symptoms No fault symptoms other than the SRS indicator illumi nates There is a risk that the SRS will not work with this fault code Cause of fault Breakage in the ignition cable or connector between the airbag module and the control unit Alternatively break age in the airbag module resistance too high in the igniter or in the contact reel Action To be able to find the cause of the fault troubleshoot according to the following procedures Follow the proce dures carefully Do not skip over an item before the cause of the fault is localized See Routines for a Damaged Faulty Airbag Module page 46 concerning the handling of a damaged airbag module Troubleshooting T

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