BENDIX BW1650 User's Manual
Contents
1. Bendix ET 2 Electronic Treadle TREADLE COVER POTENTIOMETER DOUBLE RETURN SPRING PIVOT SPRING ROLLER MOUNTING BASE CABLE ASSEMBLY FIGURE 1 ET 2 ELECTRONIC TREADLE DESCRIPTION The ET 2 is an electronic throttle On electronically controlled diesel engines the ET 2 treadle fulfills the same function as a conventional mechanical throttle The ET 2 treadle controls engine speed by interacting with an electronic fuel management controller on the engine rather than transmitting a mechanical force from the throttle pedal to the engine governor The main components of the ET 2 throttle are a cast aluminum mounting base and treadle a rubber treadle cover a potentiometer variable resistor and a roller assembly The potentiometer is specific to each engine application OPERATION The ET 2 treadle provides smooth graduated throttle control through the function of its variable resistor or potentiometer The ET 2 treadle receives its supply voltage from the engine control unit The lever shaft connects the roller assembly to the potentiometer so that any movement of the treadle rotates the potentiometer As the potentiometer rotates its resistance changes This way the potentiometer communicates the throttle position to the fuel control system by changing resistance returning more or less of the supplied voltage back to the electronic engine controller lf the driver does not re2. in place push the lever shaft through the treadle ears 10 11 12 With the ET 2 treadle on its side as mentioned above the lever shaft should protrude from the treadle with its snap ring groove visible Secure the lever shaft with its snap ring 8 Turn the ET 2 treadle upright Place the potentiometer 2 in the position shown in Figure 4 with its connector facing the rear of ET 2 treadle Secure the potentiometer with its screws 3 Torque to 20 inch pounds 5 Install the treadle cover 1 and cable assembly as shown in Figure 4 Clip the wire from the spring assembly so that the straight end of the springs rest against the underside of the treadle Make sure the ET 2 treadle has smooth even treadle movement Also perform Operational Test steps 3 7 before installing the ET 2 treadle Install the ET 2 treadle on the vehicle BW1650 2004 Bendix Commercial Vehicle Systems LLC All rights reserved 6 2004 Printed in U S A
3. 10 washer 7 and snap rings 8 for cracks or deterioration Replace as necessary OPERATIONAL TEST Perform these tests only if the vehicle s throttle does not appear to operate as expected Test 1 For Mack and DDC engines 1 Unplug the cable assembly from the potentiometer s integral connector by lifting the lock tab and pulling the connectors until they disengage Inspect cable assembly for loose terminals frayed wires corrosion POWER SUPPLY 9 16 VDC PIN C RESISTOR tie ROUND TEST LOAD 47 000 OHM FOR PIN B DETROIT DIESEL VOUT 300 000 OHM OUTPUT FOR MACK PIN A VREF INPUT POTENTIOMETER POTENTIOMETER PC NO ON THIS SURFACE FIGURE 5 ET 2 TREADLE ELECTRICAL TEST SCHEMATIC FOR THE DETROIT DIESEL CONNECTOR wear or physical damage Check end to end electrical continuity at terminals NOTE Potentiometer pin locations will remain constant See Figure 5 However cable assembly connector pin out may vary from engine to engine 2 Remove the ET 2 treadle from the vehicle 3 Secure the ET 2 treadle to a smooth flat surface in such a way that it does not twist the unit 4 Connect the potentiometer to the volt meter and power supply as shown in Figure 5 NOTE Power supply can be a 12 VDC vehicle battery in good condition and with known voltage output 5 Verify that the closed throttle idle output voltage as a percentage of supply voltage is within the limits listed in
4. Figure 2 6 Depress the treadle to its full throttle position The output voltage as a percentage of supply voltage should be within the limits listed in Figure 2 e g Testing a Detroit Diesel ET 2 Treadle Potentiometer Battery 10 VDC Full throttle 9 VDC 9 10 x 100 90 7 Make several full applications and record idle position voltage each time Verify that idle position voltage does not vary by more than 4 02 volts If the ET 2 treadle does not operate within its specified ranges service the unit or replace it with a new ET 2 treadle available at your nearest Bendix parts outlet PACKARD ELECTRIC CONNECTOR 12010717 CONNECTOR X INPUT PIN 3 OUTPUT PIN 2 GROUND PIN 1 PACKARD ELECTRIC CONNECTOR 12015793 CONNECTOR Y FIGURE 6 ET 2 TREADLE ELECTRICAL TEST SCHEMATIC FOR THE CUMMINS CONNECTOR Test 2 For Cummins engines featuring a separate potentiometer and idle validation switch To test the potentiometer on the vehicle use steps 1 through 8 Alternatively instructions for carrying out a bench test is covered in instructions 11 through 16 1 2 5 First construct the breakout harness shown in Figure 6 Insert connector X on the breakout harness into the connector leading from the potentiometer Then insert connector Y on the breakout harness into the connector leading from the dashboard wire harness Next insert pin 1 into the ground position on a voltmet
5. culate the switch point percentage using the formula locations will remain constant see Figure 5 However below cable assembly connector pin out may vary from engine Switch point percentage Vx V1 V2 V1 100 to engine Vx Output voltage when the switch changed 11 Remove the ET 2 treadle from the vehicle V1 idle voltage 12 Secure the ET 2 treadle to a smooth flat surface in V2 full throttle voltage such a way that it does not twist the unit 13 Connect the potentiometer to the volt meter and power supply as shown in Figure 5 NOTE Power supply can be a 12 VDC vehicle battery in good condition and with known voltage output 14 Verify that the closed throttle idle output voltage as a S D ae percentage of supply voltage is within the limits listed in Figure 2 15 Depress the treadle to its full throttle position The output voltage as a percentage of supply voltage should be within the limits listed in Figure 2 e g Testing a Detroit Diesel ET 2 Treadle Potentiometer Battery 10 VDC Full throttle 9 VDC 9 10 x 100 90 Pai ce ROUND 16 Make several full applications and record idle position ee voltage each time Verify that idle position voltage does 47 000 OHM yl mo not vary by more than 4 02 volts If the ET 2 LCA IIl a Sass des eal OUTPUT treadle does not operate within its specified ranges PIN A service the unit or replace it with a new ET 2 treadle INPUT availab
6. e unit or replace it with a new ET 2 treadle REMOVAL 1 Park the vehicle on a level surface and block the wheels and or hold the vehicle by means other than the air brakes Drain the air pressure from all vehicle reservoirs Unplug the cable assembly at the opposite end of the potentiometer Disconnect by lifting the lock tab and pulling the connectors until they disengage Remove the ET 2 treadle from the vehicle Vs SUPPLY VOLTAGE Closed Throttle open Range 5 17 Open Throttle full Range 70 81 LOCK TAB V3 LOGIC HIGH AT IDLE IDLE V2 LOGIC LOW AT IDLE VALIDATION SWITCH Vs SUPPLY VOLTAGE PEDAL V1 POSITION SENSOR OluF APS TEST LOAD 47000 OHM IVS GROUND OUTPUT GROUND POTENTIOMETER SET VOLTAGE AND PC NO SHOWN HERE VS 4 INPUT APS GROUND Pen nae 1 IVS GROUND OUTPUT SIGI 2 IVS V2 FIGURE 8 ET 2 TREADLE ELECTRICAL TEST SCHEMATIC FOR THE CUMMINS CONNECTOR INSTALLATION 1 Install the assembled ET 2 treadle on the vehicle 2 Reconnect the cable connector by plugging it into the potentiometer s integral connector and pushing until the lock tab snaps into place DISASSEMBLY The following instructions present a major disassembly of the ET 2 treadle They are included for reference only Several replacement parts and maintenance kits that do not require full disassembly are available The instructions provided with tho
7. er Then insert pin 2 into the positive position on a volt meter Disconnect the idle validation switch cable from the dashboard wire harness Connect an ohmmeter to pins A and B on the connector leading from the idle validation switch The positive lead should be connected to pin A and the negative lead should be connected to pin B Turn the vehicle s ignition key to the battery on position This supplies a 5 volt input to the potentiometer Since the idle validation switch is no longer connected a fault code may be triggered on some vehicles This fault code will be reset at the end of this test 6 Record the output voltage when the pedal is in the idle The following instructions are for a bench test for the position V1 Then slowly depress the pedal When potentiometer used with Cummins engines the ohm meter shows that the resistance has changed from overload to about 003 ohms or from 003 ohms to overload stop depressing the pedal Record the voltage Vx registered with the pedal in this position Then press the pedal to the full throttle position and record the output voltage V2 10 Unplug the cable assembly from the potentiometer s integral connector by lifting the lock tab and pulling the connectors until they disengage Inspect cable assembly for loose terminals frayed wires corrosion wear or physical damage Check end to end electrical continuity at terminals NOTE Potentiometer pin 7 Cal
8. est circuit following the circuit diagram shown in Figure 8 To make the test circuit connect the test load resistor 47 000 Ohms and a capacitor 01 Microfarads across pins 3 and 4 of the potentiometer Then connect a voltmeter to the lead ends of the test circuit Next connect a 5 volt power supply to the potentiometer at pin 4 APS ground and pin 5 supply voltage Caution Sensor may be damaged if supply exceeds 5 volts Now the installer should read the set voltage value marked on the potentiometer Rotate the potentiometer until the voltmeter reads the same voltage as shown on the potentiometer within 02 volts Next screw and lock the potentiometer in place torque to 25 inch pounds 5 The sleeves lock into the body of the potentiometer for easy removal and reassembly Test 4 For CAT engines 1 Securely clamp the treadle Mounting Plate 6 2 For Caterpillar Potentiometers Aligning the drive slot the Potentiometer 1 engages the drive tang at the end of the Cam Follower Drive Shaft see Figure 4 Rotate the Potentiometer clockwise until the first set of mounting holes align Secure using two screws 2 torque to 20 2 in Ibs To test the Caterpillar sensor construct the test circuit shown in Figure 7 Connect both pin B and pin C into a voltmeter Set the voltmeter to the settings described in Figure 7 Record the output values in Figure 2 If the unit does not operate within the specified ranges service th
9. le at your nearest Bendix parts outlet POTENTIOMETER Test 3 For Cummins engines with integrated switch and sensor ISS For use only with the Cummins Celet i Oe a on ar Plus and later editions of the ECU This sensor can SURFACE not be used to replace the separate potentiometer amp idle validation switch To do this a new ET 2 treadle with the ISS must be purchased FIGURE 7 ET 2 TREADLE ELECTRICAL TEST SCHEMATIC FOR THE CUMMINS CONNECTOR Test 1 Where the set resistance and voltage is shown on a label The Cummins potentiometer on the ET 2 8 The switch point percentage should be between 3 to treadle has an integral idle validation switch It also has a 10 If it is not with in this range adjust the set resistance value marked on the cover which needs to potentiometer by loosening the mounting screws and be used to properly install the potentiometer The drive turning the potentiometer within the range allowed by slot in the potentiometer should engage with the drive the mounting holes Repeat steps 1 7 again If you can tang at the end of the drive shaft Next rotate the not obtain the proper switch point percentage replace potentiometer until the hole in the metal sleeve matches with a new ET 2 treadle available at your nearest the mounting holes on the actuator base Loosely screw Bendix parts outlet the potentiometer in place but do not tighten Connect an ohmmeter to pins 3 APS output and 4 APS ground as sh
10. observed at all times 1 Park the vehicle on a level surface apply the parking brakes and always block the wheels Always wear safety glasses 2 Stop the engine and remove ignition key when working under or around the vehicle When working in the engine compartment the engine should be shut off and the ignition key should be removed Where circumstances require that the engine be in operation EXTREME CAUTION should be used to prevent personal injury resulting from contact with moving rotating leaking heated or electrically charged components 3 Do not attempt to install remove disassemble or assemble a component until you have read and thoroughly understand the recommended procedures Use only the proper tools and observe all precautions pertaining to use of those tools 4 Ifthe work is being performed on the vehicle s air brake system or any auxiliary pressurized air systems make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle If the vehicle is equipped with an AD IS air dryer system or a dryer reservoir module be sure to drain the purge reservoir 5 Following the vehicle manufacturer s recommended procedures deactivate the electrical system in a manner that safely removes all electrical power from the vehicle 6 Never exceed manufacturer s recommended pressures 7 Never connect or disconnect a hose or line containing pressure it may whip Never remove a com
11. our nyliner bearings 10 on the mounting base and treadle 2 Place the treadle ears outside the mounting base ears so that the holes line up 3 Install the pivot spring 11 into the base and treadle The curved end of the spring fits into a small hole in the treadle and the straight end fits into a small hole in the mounting base 4 The pivot pin 9 should slide through the holes in the ears of the treadle and base assembly then through the center of the spring Secure the pin with its snap ring 8 Make sure the pivot spring is straight and is seated in its holes 5 The installation of the remaining components is much easier if the inner and outer springs 12 amp 13 are compressed and caged This can be done with a short piece of wire or even a paper clip The springs should be compressed so that their ends are approximately one inch apart Place the spring support 14 inside the caged spring assembly Then insert the springs into the roller assembly 15 The curved ends of the springs fit over the small bar directly behind the roller In order to install the lever shaft 4 the roller assembly with its springs and spring support and the washers 5 amp 7 must be aligned This can be done by resting the ET 2 treadle on its side with the smaller ear of the treadle facing up Insert the washers as shown in Figure 4 Washer 5 has the larger diameter 520 While holding the roller assembly
12. own in Figure 8 Now the installer should read the set resistance value marked on the label Rotate the 9 After a successful test the vehicle may be returned to service Closed Throttle open Range 10 20 Open Throttle full Range 75 90 PIN A VREF INPUT 8V 2000 OHM 5 RESISTOR PEDAL POSITION SENSOR PWM 47 000 OHM 5 RESISTOR PIN C 2 GROUND BLACK POTENTIOMETER VOLTMETER V gt Caterpillar output voltage is Pulse Width Modulated FIGURE 8 ET S TREADLE ELECTRICAL TEST SCHEMATIC FOR THE CATERPILLAR CONNECTOR potentiometer until the ohmmeter reads the same resistance as shown on the label within 10 Ohms Next while holding the potentiometer at the set resistance screw and lock the potentiometer in place torque to 25 inch pounds 5 The sleeves lock into the body of the potentiometer for easy removal and reassembly Test 2 Where the potentiometer has no label but has engraved set voltage shown The Cummins potentiometer on the ET 2 treadle has an integral idle validation switch It also has a set voltage value marked on the cover which needs to be used to properly install the potentiometer The drive slot in the potentiometer should engage with the drive tang at the end of the drive shaft Next rotate the potentiometer until the hole in the metal sleeve matches the mounting holes on the actuator base Loosely screw the potentiometer in place but do not tighten Construct the t
13. ponent or plug unless you are certain all system pressure has been depleted 8 Use only genuine Bendix replacement parts components and kits Replacement hardware tubing hose fittings etc must be of equivalent size type and strength as original equipment and be designed specifically for such applications and systems 9 Components with stripped threads or damaged parts should be replaced rather than repaired Do not attempt repairs requiring machining or welding unless specifically stated and approved by the vehicle and component manufacturer 10 Prior to returning the vehicle to service make certain all components and systems are restored to their proper operating condition PC NO o 560320 TREADLE MOUNTING BASE FIGURE 4 EXPLODED VIEW PREVENTIVE MAINTENANCE GENERAL Perform the following tests and inspections at the prescribed intervals If the ET 2 treadle does not function as described repair it or replace it with a new unit available at any authorized Bendix parts outlet EVERY 3 MONTHS 25 000 MILES OR 900 OPERATING HOURS 1 Remove any accumulated contaminants and visually inspect the exterior of the ET 2 treadle for physical damage or excessive corrosion 2 Inspect electrical connections and cable assembly for signs of corrosion wear or physical damage Replace as necessary 3 Inspect springs 11 12 13 for signs of corrosion or pitting Replace as necessary 4 Inspect bearings
14. quest engine power the throttle is in the idle or closed throttle position In this state the potentiometer significantly reduces the amount of supply voltage returned to the engine control unit See Figure 2 As the driver depresses the ET 2 treadle output voltage increases see Figure 3 The potentiometer allows an increased amount of its supply voltage to return to the engine control unit which in turn increases the engine s speed In the full or open throttle position the driver has fully depressed the ET 2 treadle This is the state of least potentiometer resistance The ET 2 treadle returns the maximum percentage of supply voltage to the engine control unit See Figure 2 Engine Idle Throttle Full Throttle Manufacturer Closed Open CAT 13 21 79 89 Cummins 8 18 70 80 Detroit Diesel 6 14 86 94 Mack 10 20 70 85 FIGURE 2 ET 2 TREADLE OUTPUT VOLTAGE AS A PERCENTAGE OF SUPPLY VOLTAGE ET 2 TREADLE OUTPUT VOLTAGE CLOSED THROTTLE FIGURE 3 ET 2 TREADLE OUTPUT VOLTAGE OPEN THROTTLE Figure 3 illustrates the relationship between throttle position and engine RPM Potentiometer performance will vary for each engine application therefore potentiometers must not be interchanged WARNING PLEASE READ AND FOLLOW THESE INSTRUCTIONS TO AVOID PERSONAL INJURY OR DEATH When working on or around a vehicle the following general precautions should be
15. se items should be followed in lieu of the steps presented here Refer to Figure 4 throughout the procedures 1 Remove the treadle cover 1 2 Remove the pivot pin s snap ring 8 3 Remove the pivot pin 9 and the two nyliner bearings 10 from the treadle s exterior Also remove the two nyliner bearings 10 from the mounting base 4 Remove the pivot spring 11 5 Remove the screws 3 that secure the potentiometer 2 to the treadle Remove the potentiometer 6 Remove the lever shafts snap ring 5 7 Remove the lever shaft 4 and the washer 7 Then remove the roller assembly 15 the inner washer 5 and the nyliner bearing 6 from the treadle Separate the treadle from the mounting base 8 The roller assembly consists of the lever roller two springs 12 amp 13 anda spring support 14 Remove the springs and the spring support from the lever CLEANING amp INSPECTION 1 Use mineral spirits or an equivalent solvent to clean all metal parts Be sure to thoroughly dry the parts 2 Inspect the treadle and mounting base for severe corrosion pitting or cracks Replace as necessary Superficial corrosion and or pitting is acceptable 3 Inspect the cable assembly for loose or frayed wires physical damage or any contaminants on the connectors Check end tend electrical continuity at terminals Replace as necessary ASSEMBLY Refer to Figure 4 throughout the assembly procedure 1 Install the f
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