Actron® AutoTroubleShooter™ User Manual
Contents
1. 1 Insert BLACK test lead into COM test lead jack 2 Insert RED test lead into C V Q test lead jack 3 Turn multimeter rotary switch to gt function 4 Touch RED and BLACK test leads together to test continuity Listen for tone to verify proper op eration 5 Connect BLACK test lead to one side of switch 6 Connect RED test lead to other side of switch Listen for tone e If you hear tone The switch is closed If you don t hear tone The switch is open 7 Operate switch Listen for tone If you hear tone The switch is closed If you don t hear tone The switch is open 8 Repeat Step 7 to verify switch op eration Good Switch Tone turns ON and OFF as you operate switch Bad Switch Tone always ON or tone always OFF as you operate switch Testing Solenoids and Relays This test checks to see if a solenoid or relay have a broken coil If the coil tests good it is still possible that the relay or solenoid are defective The relay can have contacts that are welded or worn down and the solenoid may stick when the coil is energized This test does not check for those potential problems To test Solenoids and Relays see Fig 18 Fig 18 Relay or Solenoid 1 Insert BLACK test lead into COM test lead jack 2 Insert RED test lead AV Q gt test lead jack 3 Turn multimeter rotary switch to 2000 function Most s2. Listen for tone e If you hear tone Circuit is closed or shorted If you don t hear tone Circuit is open Testing Diodes A diode is an electrical component that allows current to only flow in one direc tion When a positive voltage generally greater than 0 7V is applied to the an ode of adiode the diode will turn on and allow current to flow If this same volt age is applied to the cathode the diode would remain off and no current would flow Therefore in order to test a diode you must check it in both directions i e anode to cathode and cathode to an ode Diodes are typically found in alter nators on automobiles Performing Diode Test see Fig 13 Fig 13 Cathode Anode 1 Insert BLACK test lead into COM test lead jack 2 Insert RED test lead into AV Q gt test lead jack 3 Turn multimeter rotary switch to function 4 Touch RED and BLACK test leads together to test continuity Check display should reset to 0 00 5 Disconnect one end of diode from circuit Diode must be totally isolated from circuit in order to test its functional ity 6 Connect RED and BLACK test leads across diode and view dis play Display will show one ofthree things A typical voltage drop of around 0 7V A voltage drop of 0 volts A 1 will appear indicating the mul timeter is overranged 7 Switch RED and BLACK test leads and repeat Step
3. MAP sensor manufacturer Frequency Type Sensor e Verify hand held vacuum pump is at 0 in of vacuum Display reading should be approxi mately 4770RPM 5 for Ford MAP sensors only For other frequency type MAP sen sors refer to vehicle service manual for MAP sensor specifications It is O K if last two display digits change slightly while vacuum is held constant Remember to multiply display reading by 10 to get actual RPM To convert RPM to Frequency or vice versa use equation below PM 30 Equation Only Valid for Multimeter in 4 Cylinder RPM Position 13 Operate Sensor Frequency e Slowly apply vacuum to MAP sen sor Never exceed 20 in of vacuum because damage to MAP sensor may result e Display reading should decrease in voltage or RPM as vacuum to MAP sensor is increased Refer to vehicle service manual for charts relating voltage and fre quency drop to increasing engine vacuum Use equation above for Frequency and RPM conversions 14 Test Results Good Sensor e Sensor output voltage or frequency RPM are within manu facturers specifications at 0 in of vacuum Sensor output voltage or frequency RPM decrease with increasing vacuum Bad Sensor Sensor output voltage or frequency RPM are not within manufactur ers specifications at 0 in of vacuum Sensor output voltage or frequency RPM do not change with increas ing vacuum Mass Air Flow MAF
4. Note range setting for cor rect units If display reading is 10Q or less subtract test lead resis tance found in Step 3 from above reading Compare reading to manu facturers specifications for fuel injector coil resistance e This information is found in vehicle service manual 8 Test Results Good Fuel Injector resistance Re sistance of fuel injector coil is within manufacturers specifications Bad Fuel Injector resistance Resis tance of fuel injector coil is not within manufacturers specifications NOTE If resistance of fuel injector coil is within manufacturers specifi cations the fuel injector could still be defective It is possible that the fuel injector is clogged or dirty and that is causing your driveability prob lem Testing Engine Sensors In the early 1980 s computer controls were installed in vehicles to meet Federal Government regulations for lower emissions and better fuel economy To do its job a computer controlled engine uses electronic sensors to find out what is happening in the engine The job of the sensor is to take something the computer needs to know such as engine temperature and convert it to an electrical signal which the computer can understand The digital multimeter is a useful tool for checking sensor operation Oxygen 0 Type Sensors Titania Type Oxygen Sensor The Oxygen Sensor produces a voltage or resistance based on the amount of oxygen in the exhaust str
5. 6 8 Test Results If the display showed A voltage drop of 0 volts in both directions then the diode is shorted and needs to be replaced A 1 appears in both directions then the diode is an open circuit and needs to be replaced e The diode is good if the display reads around 0 5V 0 7V in one di rection and a 1 appears in the other direction indicating the multi meter is overranged Measuring Engine RPM RPM refers to revolutions per minute When using this function you must multi ply the display reading by 10 to get actual RPM If display reads 200 and the multim eter is set to 6 cylinder RPM the actual engine RPM is 10 times 200 or 2000 RPM To measure Engine RPM see Fig 14 Fig 14 Typical Ignition Coil 1 Insert BLACK test lead into COM test lead jack 2 Insert RED test lead into ACV Q gt test lead jack 3 Connect RED test lead to TACH RPM signal wire e If vehicle is DIS Distributorless Ignition System then connect RED test lead to the TACH signal wire going from the DIS module to the vehicle engine computer refer to vehicle service manual for location of this wire For all vehicles with distributors connect RED test lead to negative side of primary ignition coil refer to vehicle service manual for loca tion of ignition coil 4 Connect BLACK test lead to a good vehicle ground 5 Turn multimeter rotary switch to correct CYLINDER select
6. 7 Multimeter display should vary from 10 to 50 as vehicle changes from lean to rich Measuring Fuel Injector Resistance Fuel injectors are similar to solenoids They contain a coil that is switched ON and OFF by the vehicle computer This test measures the resistance of this coil to make sure it is not an open circuit Shorted coils can also be detected if the specific manufacturer resistance of the fuel injector is known Test Procedure see Fig 30 Fig 30 Typical Fuel Injector Insert BLACK test lead into COM test lead jack Insert RED test lead into C V Q test lead jack Turn multimeter rotary switch to 2000 range Touch RED and BLACK multimeter leads together and view reading on display Display should read typically 0 2 1 50 If display reading was greater than 1 50 check both ends of test leads for bad connections If bad connec tions are found replace test leads Disconnect wiring harness from fuel injector Refer to vehicle ser vice manual for procedure 5 Connect RED and BLACK test leads across fuel injector pins Make sure you connect test leads across fuel injector and not the wir ing harness Turn multimeter rotary switch to desired OHM range If the approximate resistance is unknown start at the largest OHM range and decrease to the appropriate range as required see Setting the Range on page 6 7 View reading on display
7. BLACK test lead to other end Turn multimeter rotary switch to 200KQ range View reading on display while flex ing ignition wire and boot in sev eral places e Typical resistance range is 3KQ to 50KQ or approximately 10KQ per foot of wire Refer to vehicle service manual for your vehicles resistance range As you flex ignition wire the dis play should remain steady Test Results Good Ignition Wire Display reading is within manufacturers specifica tion and remains steady while wire is flexed Bad Ignition Wire Display reading erratically changes as ignition wire is flexed or display reading is not within manufacturers specification Hall Effect Sensors Switches Hall Effect sensors are used whenever the vehicle computer needs to know speed and position of a rotating object Hall Effect sensors are commonly used in ignition systems to determine cam shaft and crankshaft position so the ve hicle computer knows the optimum time to fire the ignition coil s and turn on the fuel injectors This test checks for proper operation of the Hall Effect sensor switch Test Procedure see Fig 27 1 Remove Hall Effect Sensor from vehicle Refer to vehicle service manual for procedure 2 Connect 9V battery to sensor POWER and GROUND pins Connect positive terminal of 9V battery to sensor POWER pin Connect negative terminal of 9V battery to sensor GROUND pin e Refer to ill
8. Sensors This sensor sends a signal to the com puter indicating the amount of air enter ing the engine Depending on the sen sor design the signal may be a dc volt age low frequency or high frequency type The CP7677 can only test the dc voltage and low frequency type of MAF sensors The high frequency type sensors output a frequency that is too high for the CP7677 to measure The high frequency type MAF is a 3 pin sen sor used on 1989 and newer GM ve hicles Refer to vehicle service manual for the type of MAF sensor your vehicle uses Test Procedure see Fig 35 1 Insert BLACK test lead into COM test lead jack 2 Insert RED test lead into ACV Q test lead jack 3 Connect BLACK test lead to good vehicle ground 4 Connect RED test lead to MAF signal wire e Refer to vehicle service manual for location of MAF signal wire You may have to backprobe or pierce MAF signal wire in order to make connection e Refer to vehicle service manual for best way to connect to MAF signal wire 5 Turn Ignition Key ON but do not start engine 6 Turn multimeter rotary switch to Fig 35 Frequency Only DC Ground Only Black Typical GM 1988 amp older Low Frequency type MAF Sensor 8 Operate Sensor Start engine and let idle Display reading should increase in voltage from Key On Engine OFF for DC type MAF sensors increase in RPM from Key On Engine OFF for Low Fr
9. actron mem actron je LILL Auto TroubleShooter OPERATING INSTRUCTIONS CP7677 SAFETY GUIDELINES TO PREVENT ACCIDENTS THAT COULD RESULT IN SERIOUS INJURY AND OR DAMAGE TO YOUR VEHICLE OR TEST EQUIPMENT CAREFULLY FOLLOW THESE SAFETY RULES AND TEST PROCEDURES Always wear approved eye protection Always operate the vehicle in a well ventilated area Do not inhale exhaust gases they are very poisonous Always keep yourself tools and test equipment away from all moving or hot engine parts Always make sure the vehicle is in park Automatic transmission or neutral manual transmission and that the parking brake is firmly set Block the drive wheels Never lay tools on vehicle battery You may short the terminals together causing harm to yourself the tools or the battery Never smoke or have open flames near vehicle Vapors from gasoline and charging battery are highly flammable and explosive Never leave vehicle unattended while running tests Always keep a fire extinguisher suitable for gasoline electrical chemical fires handy Always use extreme caution when working around the ignition coil distributor cap ignition wires and spark plugs These components contain High Voltage when the engine is running Always turn ignition key OFF when connecting or disconnecting electrical components unless otherwise instructed Always follow vehicle manufacturer s warnings cautions and service procedu
10. and functions and explains how to use these functions to make various measurements actron CP7677 5 DWELL RPMxto mV V QOKOQ MQ gt Or LOLOL a mA A 4cyL 6CYL 8cyL Connect Test Leads O O gO TM Alligator Clip Adapters Some multimeter tests and measurements are more easily done using alligator clips instead of test prods For these tests push the crimp end of the alligator clip onto the test prod If the crimp on the alligator clip becomes loose then remove the alligator clip from the test prod and re crimp using a pair of pliers Functions and Display Definitions 1 ROTARY SWITCH Switch is rotated to select a function 2 DC VOLTS This function is used for measuring DC Direct Current Voltages in the range of 0 to 1000V 3 OHMS This function is used for measuring the resistance of a component in an elec trical circuit in the range of 0 19 to 20MQ Q is the electrical symbol for Ohms 4 DIODE CHECK CONTINUITY TESTS This function is used to check whether a diode is good or bad It is also used for fast continuity checks of wires and ter minals An audible tone will sound if a wire and terminal are good 5 HOLD Press HOLD button to retain data on display In the hold mode the H an nunciator is displayed 6 TEST LEAD JACKS BLACK Test Lead is al COM ways inserted inthe COM jack RED Test Lead is in serted in the jack corre spon
11. connections or open al ternator field current e Refer to vehicle service manual for further diagnosis Ignition System Testing The ignition system is responsible for providing the spark that ignites the fuel in the cylinder Ignition system components that the digital multimeter can test are the primary and secondary ignition coil resistance spark plug wire resistance hall effect switches sensors reluctance pick up coil sensors and the switching action of the primary ignition coil Ignition Coil Testing This test measures the resistance of the primary and secondary of an ignition coil This test can be used for distributorless ignition systems DIS provided the primary and secondary ig nition coil terminals are easily acces sible Test Procedure 1 If engine is HOT let it COOL down before proceeding Disconnect ignition coil from ig nition system Insert BLACK test lead into COM test lead jack see Fig 24 Connect test leads Connect RED test lead to primary ignition coil positive terminal Connect BLACK test leadto primary ignition coil negative terminal Referto vehicle service manual for location of primary ignition coil ter minals View reading on display Subtract test lead resistance found in Step 6 from above reading If vehicle is DIS repeat Steps 7 and 8 for remaining ignition coils Fig 24 Coil Secondary Typical Cylindrical Ig
12. ignition systems to determine cam shaft and crankshaft position so the ve hicle computer knows the optimum time to fire the ignition coil s and turn on the fuel injectors This test checks the reluc tance sensor for an open or shorted coil This test does not check the air gap or voltage output of the sensor Test Procedure see Fig 28 3 Connect RED test lead to either sensor pin 4 Connect BLACK test lead to re maining sensor pin 5 Turn multimeter rotary switch to 2KQ range 6 View reading on display while flex ing sensor wires in several places Typical resistance range is 150 10002 Refer to vehicle service manual for your vehicles resistance range Fig 28 Reluctance Sensor As you flex sensor wires the display should remain steady 7 Test Results 2 Reluctor lt Ring Good Sensor Display reading is within manu facturers specification and remains steady while sensor wires are flexed Magnet g Red N Black Bad Sensor Display reading erratically changes as sensor wires are flexed or display reading is not within 1 Insert BLACK test lead into COM test lead jack 2 Insert RED test lead C VQ test lead jack into manufacturers specifi cation Ignition Coil Switching Action This test checks to see if the negative terminal of the primary ignition coil is getting switched ON and OFF via th
13. in resistance as sen sor is opened or closed Manifold Absolute Pressure MAP and Barometric Pressure BARO Sensors This sensor sends a signal to the com puter indicating atmospheric pressure and or engine vacuum Depending on the type of MAP sensor the signal may be a dc voltage or a frequency GM Chrysler Honda and Toyota use a dc voltage MAP sensor while Ford uses a frequency type For other manufactur ers refer to vehicle service manual for type of MAP sensor used Test Procedure see Fig 34 1 Insert BLACK test lead into COM test lead jack 2 Insert RED test lead into C VQ test lead jack 3 Disconnect wiring harnc U and vacuum line from MAP sensor 4 Connect jumper wire between Pin A on wiring harness and sensor 5 Connect another jumper wire be tween Pin C on wiring harness and sensor 6 Connect RED test lead to sensor Pin B 7 Connect BLACK test lead to good vehicle ground 8 Make sure test leads and jumper wires are not touching each other 9 Connect a hand held vacuum pump to vacuum port on MAP sen sor 10 Turn Ignition Key ON but do not start engine 11 Turn multimeter rotary switch to e 20V range for DC type MAP sen sors e 4 Cylinder RPM position for Fre quency type MAP sensors 12 View reading on display DC Volts Type Sensor e Verify hand held vacuum pump is at 0 in of vacuum e Display reading should be approxi mately 3V or 5V depending on
14. lead jack 3 Insert RED test lead into C VQ test lead jack 4 Connect RED test lead to positive terminal of battery 5 Connect BLACK test lead to nega tive terminal of battery 6 Turn multimeter rotary switch to 20V DC range 7 Crank engine for 15 seconds con tinuously while observing display 8 Test Results Compare display reading in Step 7 with chart below Voltage Temperature 9 6V or greater 70 F and Above 9 5V 60 F 9 4V 50 F 9 3V 40 F 9 1V 30 F 8 9V 20 F 8 7V 10 F 8 5V 0 F If voltage on display corresponds to above voltage vs temperature chart then cranking system is normal If voltage on display does not corre spond to chart then it is possible that the battery battery cables starting sys tem cables starter solenoid or starter motor are defective Voltage Drops This test measures the voltage drop across wires switches cables solenoids and connections With this test you can find excessive resistance in the starter sys tem This resistance restricts the amount of current that reaches the starter motor resulting in low battery load voltage anda slow cranking engine at starting Test Procedure see Fig 22 1 Disable ignition system so vehicle won t start Disconnect the primary of the igni tion coil or the distributor pick up coil or the cam crank sensor to disable the ignition system Refer to vehicle service manual for disabl
15. system for wiring defects and test the camshaft and crankshaft sensors Fuel System Testing The requirements for lower vehicle emissions has increased the need for more precise engine fuel control Auto manufacturers began using electronically controlled carburetors in 1980 to meet emission requirements Today s modern vehicles use electronic fuel injection to precisely control fuel and further lower emissions The digital multimeter can be used to test the fuel mixture control solenoid on Gen eral Motors vehicles and to mea sure fuel injector resistance ye Typical Mixture Control Solenoid Connection Mixture Control Solenoid Testing GM C 3 Mixture Control Solenoid Dwell This solenoid is located in the carbure 2 tor Its purpose is to maintain an air fuel ratio of 14 7 to 1 in order to reduce emissions This test checks to see if the 3 solenoid dwell is varying Test Description This testis rather long and detailed Refer 4 to vehicle service manual for the com plete test procedure Some important test procedure highlights you need to pay close attention to are listed below 6 1 Make sure engine is at operating temperature and running during test Refer to vehicle service manual for multimeter hook up instruc tions Turn multimeter rotary switch to 6 Cylinder Dwell position for all GM vehicles Run engine at 3000 RPM 5 Make engine run both RICH and LEAN Watch multimeter display
16. will show a minus sign on the DC Volts and DC Amps functions when test lead hook up is reversed Setting the Range Two of the most commonly asked ques tions about digital multimeters are What does Range mean and How do I know what Range the multimeter should be set to What Does Range mean Range refers to the largest value the multimeter can measure with the rotary switch in that position If the multimeter is set to the 20V DC range then the highest voltage the multimeter can mea sure is 20V in that range EXAMPLE Measuring Vehicle Battery Voltage See Fig 1 1056 A Connect Test Leads o Let s assume the multimeter is con nected to the battery and set to the 20V range The display reads 12 56 This means there is 12 56V across the battery termi nals Fig 2 actron Now assume we set the multimeter to the 2V range See Fig 2 The multimeter display now shows a 1 and nothing else This means the multi meter is being overranged or in other words the value being measured is larger than the current range The range should be increased until a value is shown on the display If you are in the highest range and the multimeter is still showing that it is overranging then the value being measured is too large for the mul timeter to measure How do I know what Range the multi meter should be set to The multimeter should be set in the lowes
17. D is in sensor wiring har ness e Refer to vehicle service manual for Oxygen Sensor wiring diagram Connect RED test lead to sensor SIGNAL pin Test Oxygen Sensor e Turn multimeter rotary switch to 2V range for Zirconia Type Sen sors 200KQ range for Titania Type Sensors Light propane torch Firmly grasp sensor with a pair of locking pliers Thoroughly heat sensor tip as hot as possible but not glowing Sen sor tip must be at 660 F to operate Completely surround sensor tip with flame to deplete sensor of oxygen Rich Condition 10 11 Multimeter display should read 0 6V or greater for Zirconia Type Sensors an Ohmic Resistance value for Titania Type Sensors Reading will vary with flame temperature While still applying heat to sensor move flame such that oxygen can reach sensor tip Lean Condition Multimeter display should read 0 4V or less for Zirconia Type Sensors an overrange condition for Tita nia Type Sensors Repeat Step 8 a few times to verify results Extinguish Flame let sensor cool and remove test leads Test Results Good Sensor e Heater Circuit resistance is within manufacturer s specification e Oxygen Sensor output signal changed when exposed to a rich and lean condition Bad Sensor e Heater Circuit resistance is not within manufacturer s specification e Oxygen Sensor output signal did not change whe
18. Measuring AC Voltage This multimeter can be used to measure AC voltages in the range from 0 to 750V To measure AC Voltages see Fig 8 1 Insert BLACK test lead into COM test lead jack 2 Insert RED test lead into APC V Q test lead jack 3 Connect RED test lead to positive side of voltage source 4 Connect BLACK test lead to nega tive side of voltage source NOTE If you don t know which side is positive and which side is nega tive then arbitrarily connect the RED test lead to one side and the BLACK to the other The multimeter automatically senses polarity and will display a minus sign when nega tive polarity is measured If you switch the RED and BLACK test leads positive polarity will now be indicated on the display Measuring negative voltages causes no harm to the multimeter 5 Turn multimeter rotary switch to desired voltage range Ifthe approximate voltage is unknown start at the largest voltage range and decrease to the appropriate range as required See Setting the Range on page 6 1 Insert BLACK test lead into COM test lead jack 2 Insert RED test lead into APC VQ test lead jack 3 Connect RED test lead to one side of voltage source 4 Connect BLACK test lead to other side of voltage source 5 Turn multimeter rotary switch to desired voltage range If the approximate voltage is un known start at the largest voltage range
19. aining sensor pin Turn multimeter rotary switch to desired OHM range If the approximate resistance is un known start at the largest OHM range and decrease to the appropri ate range as required 11 Heat up sensor Iftesting Intake Air Temperature Sen sor To heat up sensor dip sensor tip into boiling water or Heat tip with a lighter if sensor tip is metal or a hair dryer if sensor tip is plastic View and record smallest reading on display as sensor is heated You may need to decrease the range to get a more accurate read ing For all other temperature sensors Start engine and let idle until upper radiator hose is warm Turn ignition key OFF Disconnect sensor wiring harness and reconnect multimeter test leads e View and record reading on dis play 12 Test Results Good Sensor Temperature sensors HOT resis tance is at least 300Q less than its COLD resistance e The key point is that the COLD re sistance decreases with increasing temperature Bad Sensor e There is no change between the temperature sensors HOT resis tance from the COLD resistance e The temperature sensor is an open or a short circuit Position Type Sensors Position sensors are potentiometers or a type of variable resistor They are used by the computer to determine po sition and direction of movement of a mechanical device Typical position sen sor applications are throttle position sensor
20. and decrease to the appropri ate range as required See Setting the Range on page 6 6 View reading on display Note range setting for correct units NOTE 200mV 0 2V Measuring Resistance Resistance is measured in electrical units called ohms Q The digital multi meter can measure resistance from 0 10 to 20MQ or 20 000 000 ohms Infinite resistance is shown with a 1 on the left side of display See Setting the Range on page 6 You can use this multimeter to do any resistance measurement called out in the vehicle service manual Test ing ignition coils spark plug wires and some engine sensors are common uses for the OHMS Q function To measure Resistance see Fig 9 Fig 9 Unknown Resistance 1 Turn circuit power OFF To get an accurate resistance mea surement and avoid possible damage to the digital multimeter and electrical circuit under test turn off all electrical power in the circuit where the resis tance measurement is being taken 2 Insert BLACK test lead into COM test lead jack 3 Insert RED test lead into C VO test lead jack 4 Turn multimeter rotary switch to 2000 range Touch RED and BLACK multimeter leads together and view reading on display Display should read typically 0 20 to 1 50 If display reading was greater than 1 50 check both ends of test leads for bad connections If bad connec tions are found replace test leads 5 Connect RED and BLACK tes
21. cturers specification Bad Ignition Coil Resistance read ings in Steps 10 15 and 16 are not within manufacturers specification Ignition System Wires This test measures the resistance of spark plug and coil tower wires while they are being flexed This test can be used for distributorless ignition systems DIS provided the system does not mount the ignition coil directly on the spark plug Test Procedure 1 Remove ignition system wires one at a time from engine Always grasp ignition system wires on the boot when re Spark Plug Wire moving Twist the boots about a half turn while pulling gently to remove them Refer to vehicle service manual for ignition wire removal procedure Inspect ignition wires for cracks chaffed insulation and corroded ends NOTE Some Chrysler products use a positive locking terminal electrode spark plug wire These wires can only be removed from inside the dis tributor cap Damage may result if other means of removal are at tempted Refer to vehicle service manual for procedure NOTE Some spark plug wires have sheet metal jackets with the follow ing symbol gt lt This type of plug wire contains an air gap resistor and can only be checked with an oscilloscope Insert BLACK test lead into COM test lead jack see Fig 26 Insert RED test lead into ACV Q test lead jack 4 Connect RED test lead to one end of ignition wire and
22. ding to the multim eter rotary switch setting LO VO 00 DC AMPS RPM DC VOLTS DWELL AC VOLTS OHMS DIODES CONTINUITY Always connect TEST LEADS to the mul timeter before connecting them to the circuit under test 7 AC VOLTS This function is used for measuring AC Voltages in the range of 0 to 750V 8 DC AMPS This function is used for measuring DC Direct Current Amps in the range of 0 to 10A 9 DWELL This function is used for measuring DWELL on distributor ignition systems and solenoids 10 TACH This function is used for measuring engine speed RPM 11 ON OFF Press to turn power ON Press again to turn power OFF 12 DISPLAY Used to display all measurements and multimeter information Low Battery If this symbol appears in the lower left corner of the display then replace the inter nal 9V battery See Fuse and Battery re placement on page 7 Overrange Indication If 1 or 1 appears on the left side of the display then the multi meter is set to a range that is too small for the present measurement being taken Increase the range until this dis appears If it does not disappear after all the ranges for a particular function have been tried then the value being measured is too large for the multimeter to measure Zero Adjustment The multimeter will automatically zero on the Volts Amps and RPM functions Automatic Polarity Sensing The multimeter display
23. e quency type MAF sensors Rev Engine Display reading should increase in voltage from Idle for DC type MAF sensors increase in RPM from Idle for Low Frequency type MAF sensors Refer to vehicle service manual for charts relating MAF sensor voltage or fre quency RPM to increasing air flow 20V range for DC type MAF sen sors e 4 Cylinder RPM position for Low Frequency type MAF sensors View reading on display DC Volts Type Sensor e Display reading should be approxi mately 1V or less depending on MAF sensor manufacturer Low Frequency Type Sensor Display reading should be approxi mately 330RPM 5 for GM Low Frequency MAF sensors For other Low Frequency type MAF sensors refer to vehicle service manualfor MAF sensor specifications It is O K if last two display digits change slightly while Key is ON Remember to multiply display read ing by 10 to get actual RPM To convert RPM to Frequency or vice versa use equation below PM 30 Equation Only Valid for Multim eter in 4 Cylinder RPM Position Frequency Use equation above for Fre quency and RPM conver sions Test Results Good Sensor e Sensor output voltage or frequency RPM are within manufacturers specifications at Key ON Engine OFF e Sensor output voltage or frequency RPM increase with increasing air flow Bad Sensor e Sensor output voltage or frequency RPM are not within
24. e ignition module and camshaft crank shaft position sensors This switching action is where the RPM or tach signal originates This test is primarily used for a no start condition vehicle service manual for location of this wire e For all vehicles with distributors connect RED test lead to negative side of primary ignition coil refer to vehicle service manual for loca tion of ignition coil 4 Connect BLACK test lead to a good Test Procedure see Fig 29 Fig 29 Typical Ignition 1 Insert BLACK test lead into COM test lead jack 2 Insert RED test lead into ACV Q test lead jack 3 Connect RED test lead to TACH signal wire e If vehicle is DIS Distributorless Ignition System then connect RED test lead to the TACH signal wire going from the DIS module to the vehicle engine computer refer to vehicle ground 5 Turn multimeter rotary switch to correct CYLINDER selec tion in RPM 6 View reading on display while engine is cranking e Typical cranking RPM range is 50 275 RPM depending on temperature size of engine and battery condition e Refer to vehicle service manual for specific vehicle cranking RPM range 7 Test Results Good Coil Switching Action Display reading indicated a value consistent with manufacturers specifications Bad Coil Switching Action e Display read zero RPM meaning the ignition coil is not being switched ON and OFF Check ignition
25. eam A low voltage high resistance indicates alean exhaust too much oxygen while a high voltage low resistance indicates a rich exhaust not enough oxygen The com puter uses this voltage to adjust the air fuel ratio The two types of O Sensors commonly in use are Zirconia and Tita nia Refer to illustration for appearance differences of the two sensor types Exposed flat element Zirconia Type Oxygen Sensor Flutes Test Procedure see Fig 31 1 If engine is HOT let it COOL down 5 Test heater circuit before proceeding If sensor contains 3 or more wires 2 Remove Oxygen Sensor from ve then your vehicle uses a heated O hicle sensor 3 Insert BLACK test lead into COM e Refer to vehicle service manual for test lead jack location of heater pins 4 Insert RED test lead into e Connect RED test lead to either C VQ test lead jack heater pin Fig 31 Ground 1 wire or 3 wire Ground is sensor housing 2 wire or 4 wire Ground is in sensor wiring Black harness Connect BLACK test lead to re maining heater pin e Turn multimeter rotary switch to 2000 range View reading on display Compare reading to manufacturer s specification in vehicle service manual Remove both test leads from sen sor Connect BLACK test lead to sen sor GROUND pin e If sensor is 1 wire or 3 wire then GROUND is sensor housing e If sensor is 2 wire or 4 wire then GROUN
26. en cir cuit where you want to measure current This is done by Disconnecting wiring harness Disconnecting wire from screw on type terminal e Unsolder lead from component if Fig 10 Electrical DC Voltage Source Testing for Continuity Continuity is a quick way to do a resis tance test to determine if a circuit is open orclosed The multimeter will beep when the circuit is closed or shorted so you don t have to look at the display Continuity checks are usually done when checking for blown fuses switch opera tion and open or shorted wires To measure Continuity see Fig 12 working on printed circuit boards e Cut wire if there is no other pos sible way to open electrical circuit Connect RED test lead to one side of disconnected circuit Connect BLACK test lead to re maining side of disconnected cir cuit Turn multimeter rotary switch to 10A DC position or 200mA posi tion View reading on display If minus sign appears on display then reverse RED and BLACK test leads Black 1 Insert BLACK test lead into COM test lead jack 2 Insert RED test lead into ACV Q test lead jack 3 Turn multimeter rotary switch to gt function 4 Touch RED and BLACK test leads together to test continuity Listen for tone to verify proper op eration 5 Connect RED and BLACK test leads across component where you want to check for continuity
27. ent Voltage Battery is Charged 12 60V or greater 100 12 45V 75 12 30V 50 12 15V 25 1 Turn Ignition Key OFF 2 Turn ON headlights for 10 sec onds to dissipate battery surface charge 3 Insert BLACK test lead into COM test lead jack 4 Insert RED test lead into ACV Q test lead jack 5 Disconnect positive battery cable 6 Connect RED test lead to positive terminal of battery 7 Connect BLACK test lead to nega tive terminal of battery 8 Turn multimeter rotary switch to 20V DC range 9 View reading on display 10 Test Results Compare display reading in Step 9 with the following chart If battery is not 100 charged then charge it before doing anymore starting charging system tests Engine Off Battery Current Draw This test measures the amount of cur rent being drawn from the battery when the ignition key and engine are both off This test helps to identify possible sources of excessive battery current drain which could eventually lead to a dead battery 1 Turn Ignition Key and all accesso ries OFF Make sure trunk hood and dome lights are all OFF See Fig 20 2 Insert BLACK test lead into COM test lead jack 3 Insert RED test lead into A or mA test lead jack Fig 20 4 Disconnect positive battery cable 5 Connect RED test lead to positive battery terminal 6 Connect BLACK test lead to posi
28. g Switches test procedure on page 13 e When you are told to operate switch then move throttle linkage Vane Air Flow Sensor e Slowly open vane door from closed to open by pushing on it with a pencil or similar object This will not harm sensor Depending on hook up the dis play reading will either increase or decrease in resistance The display reading should either start at or end at the approximate resistance value measured in Step 6 Some vane air flow sensors have an idle switch and an intake air temperature sensor in addition toa potentiometer To test idle switch see Testing Switches on page 13 When you are told to operate switch then open vane door To test intake air tempera ture sensor see Temperature Type Sensors on page 29 EGR Valve Position Remove vacuum hose from EGR valve Gr Connect hand vacuum pump to EGR valve Gradually apply vacuum to slowly open valve Typi cally 5 to 10 in of vacuum fully opens valve Depending on hook up the display reading will either increase or decrease in re sistance The display reading should either start at or end at the approximate resistance value measured in Step 6 9 Test Results Good Sensor Display reading gradually increases Fig 34 Frequency Only o Typical GM Sensor To Computer or decreases in resistance as sensor is opened and closed Bad Sensor There is no change
29. ing proce dure Insert BLACK test lead into COM test lead jack Insert RED test lead C VO test lead jack Connect test leads into Refer to Typical Cranking Voltage Loss Circuit Fig 22 Connect RED and BLACK test leads alternately between 1 amp 2 2 amp 3 4 amp If multimeter overranges turn multim eter rotary switch to the 2V DC range See Setting the Range on page 6 Crank engine until steady reading is on display Record results at each point as displayed on multimeter e Repeat Step 4 amp 5 until all points are checked Test Results Estimated Voltage Drop of Starter Circuit Components Component Voltage Switches 300mV Wire or Cable 200mV Ground 100mV Battery Cable Connectors 50mV Connections 0 0V Compare voltage readings in Step 6 with above chart Ifany voltages read high inspect com ponent and connection for defects 5 5 amp 6 6 amp 7 7 amp 9 8 amp 9 and8 amp 10 e If defects are found service as necessary Turn multimeter rotary switch to 200mV DC range Fig 22 Typical Cranking Voltage Loss Circuit Baits olenoid This is a representative sample of one type of cranking circuit Your vehicle may use a different circuit with different components or locations Consult your vehicle service manual Charging System Voltage Test This test checks the charging system to 8 Open throttle and Hold engine see if it charges the battery and
30. ion 6 Measure engine RPM while engine is cranking or running 7 View reading on display Remember to multiply display read ing by 10 to get actual RPM If display reads 200 then actual en gine RPM is 10 times 200 or 2000 RPM Measuring Dwell Dwell measuring was extremely impor tant on breaker point ignition systems of the past It referred to the length of time in degrees that the breaker points re mained closed while the camshaft was rotating Today s vehicles use electronic ignition and dwell is no longer adjust able Another application for dwell is in testing the mixture control solenoid on GM feedback carburetors To measure Dwell see Fig 15 Fig 15 Typical 1 Insert BLACK test lead into COM test lead jack 2 Insert RED test lead ACV Q test lead jack 3 Connect RED test lead to DWELL signal wire into 6 If measuring DWELL on breaker point ignition systems connect RED test lead to negative side of primary ignition coil refer to ve hicle service manual for location of ignition coil If measuring DWELL on GM mix ture control solenoids connect RED test lead to ground side or computer driven side of solenoid refer to vehicle service manual for solenoid location If measuring DWELL on any arbi trary ON OFF device connect RED test lead to side of device that is being switched ON OFF Connect BLACK test lead to a good vehicle ground Turn multimeter r
31. manufactur ers specifications at Key ON En gine OFF e Sensor output voltage or frequency RPM do not change with increas ing air flow Electrical Specifications DC Volts Range 200mV 2V 20V 200V Accuracy 0 5 rdg 5 dgts Range 1000V Accuracy 0 8 rdg 5 dgts AC Volts Range 2V 20V 200V Accuracy 0 8 rdg 5 dgts Range 750V Accuracy 1 0 rdg 4 dgts DC Current Range 200mA Accuracy 0 8 rdg 5 dgts Range 10A Accuracy 1 2 rdg 5 dgts Resistance Range 200Q 2KQ 20KQ 200KQ 2MQ Accuracy 0 8 rdg 5 dgts Range 20MQ Accuracy 1 5 rdg 5 dgts Dwell Range 4CYL 6CYL 8CYL Accuracy 3 0 rdg 5 dgts RPM Range 4CYL 6CYL 8CYL Accuracy 3 0 rdg 5 dgts Audible Continuity Buzzer sounds at approximately less than 30 50 Ohms ACTRON HAND TOOLS
32. n exposed to arich and lean condition e Oxygen sensor output voltage takes longer than 3 seconds to switch from a rich to a lean condi tion Temperature Type Sensors A temperature sensor is a thermistor or aresistor whose resistance changes with temperature The hotterthe sensor gets the lower the resistance becomes Typi cal thermistor applications are engine coolant sensors intake air temperature sensors transmission fluid temperature sensors and oil temperature sensors 9 View and record reading on dis play 10 Disconnect multimeter test leads from sensor and reconnect sen sor wiring This step does not apply to intake air temperature sensors For intake air temperature sensors leave multim eter test leads still connected to sen sor Test Procedure see Fig 32 Fig 32 Hair Typical Intake Air Temperature Sensor Black Insert If engine is HOT let it COOL down before proceeding Make sure all engine and transmis sion fluids are at outside air tem perature before proceeding with this test Insert BLACK test lead into COM test lead jack RED test lead CV Q gt test lead jack Disconnect wiring harness from sensor into If testing Intake Air Temperature Sensor Remove it from vehicle All other temperature sensors can remain on vehicle for testing Connect RED test lead to either sensor pin Connect BLACK test lead to re m
33. nition Coil 10 Test Results Pri mary Coil Typicalresistance range of primary ignition coils is 0 3 2 0 e Refer to vehicle service manual for your vehicles resistance range 11 Turn multimeter rotary switch to 4 Insert RED test lead into 200KQ range see Fig 25 HOVA test lead jack Turn multimeter rotary switch to 200Q range Touch RED and BLACK multim eter leads to gether and view reading on dis play Secondary Typical Cylindrical Ignition Coil 12 Move RED test lead to secondary ignition coil terminal e Refer to vehicle service manual for location of secondary ignition coil terminal e Verify BLACK test lead is con nected to primary ignition coil nega tive terminal 13 View reading on display 14 If vehicle is DIS repeat Steps 12 and 13 for remaining ignition coils 15 Test Results Secondary Coil e Typical resistance range of sec ondary ignition coils is 6 0 30 0KQ e Refer to vehicle service manual for your vehicles resistance range 16 Repeat test procedure for a HOT ignition coil NOTE It is a good idea to test ignition coils when they are both hot and cold because the resistance of the coil could change with tempera ture This will also help in diagnosing intermittent ignition system prob lems 17 Test Results Overall Good Ignition Coil Resistance read ings in Steps 10 15 and 16 were within manufa
34. oint This changes the accuracy of the measurement by ei ther increasing or decreasing the number of digits after the decimal point Battery and Fuse Replacement Important A 9 Volt battery must be in stalled before using the digital multim eter See procedure below for installa tion Battery Replacement 1 Turn multimeter OFF 2 Remove test leads from multimeter 3 Remove screw from battery cover 4 Remove battery cover 5 Install a new 9 Volt battery 6 Re assemble multimeter Fuse Replacement 1 Turn multimeter OFF 2 Remove test leads from multimeter 3 Remove rubber holster 4 Remove screw from battery cover battery cover and battery 5 Remove screws from back of multimeter 6 Remove back cover 7 Remove fuse 8 Replace fuse with same size and type as originally installed Use a 1 4 x 1 1 4 10A 250V fast acting fuse or a 5mm x 20mm 315mA 250V fast acting fuse 9 Re assemble multimeter Measuring DC Voltage This multimeter can be used to measure DC voltages in the range from 0 to 1000V You can use this multimeter to do any DC voltage measurement called out in the vehicle service manual The most com mon applications are measuring voltage drops and checking if the correct voltage arrived at a sensor or a particular circuit To measure DC Voltages see Fig 7 6 View reading on display Note range setting for correct units NOTE 200mV 0 2V
35. olenoids and relay coil resis tances are less than 2000 If meter overranges turn multimeter rotary switch to next higher range into 4 Connect BLACK test lead to one side of coil Connect RED test lead to other side of coil View reading on display e Typical solenoid relay coil resis tances are 200Q or less e Refer to vehicle service manual for your vehicles resistance range Test Results Good Solenoid Relay Coil Display in Step 6 is within manufacturers specification Bad Solenoid Relay Coil e Display in Step 6 is not within manu facturers specifications e Display reads overrange on every ohms range indicating an open cir cuit NOTE Some relays and solenoids have a diode placed across the coil To test this diode see Testing Di odes Starting Charging System Testing The starting system turns over the engine It consists of the battery starter motor starter solenoid and or relay and associated wiring and connections The charging system keeps the battery charged when the engine is running This system consists of the alternator voltage regulator battery and associated wiring and connections The digital multimeter is a useful tool for checking the operation of these systems No Load Battery Test Before you do any starting charging sys tem checks you must first test the bat tery to make sure it is fully charged Test Procedure see Fig 19 Fig 19 Perc
36. otary switch to correct DWELL CYLINDER posi tion View reading on display Section 2 Automotive Testing The digital multimeter is a very useful tool for trouble shooting automotive elec trical systems This section describes how to use the digital multimeter to test the starting and charging system igni tion system fuel system and engine sensors The digital multimeter can also be used for general testing of fuses switches solenoids and relays General Testing The digital multimeter can be used to test fuses switches solenoids and re lays Testing Fuses This test checks to see if a fuse is blown You can use this test to check the internal fuses inside the digital multimeter To test Fuses see Fig 16 1 Insert BLACK test lead into COM test lead jack 2 Insert RED test lead into C VO test lead jack 3 Turn multimeter rotary switch to gt function 4 Touch RED and BLACK test leads together to test continuity Listen for tone to verify proper op eration 5 Connect RED and BLACK test leads to opposite ends of fuse Listen for tone e If you hear tone Fuse is good If you don t hear tone Fuse is blown and needs to be replaced NOTE Always replace blown fuses with same type and rating Testing Switches This test checks to see if a switch Opens and Closes properly To test Switches see Fig 17 Typical Push Button Switch
37. ow you to check out automotive service manuals Do a Thorough Visual Inspection Do a thorough visual and hands on underhood inspection before starting any diagnostic procedure You can find the cause of many problems by just looking thereby saving yourself a lot of time e Has the vehicle been serviced recently Sometimes things get reconnected in the wrong place or not at all Don t take shortcuts Inspect hoses and wiring which may be difficult to see due to location e Inspect the air cleaner and ductwork for defects e Check sensors and actuators for damage e Inspect ignition wires for Damaged terminals Split or cracked spark plug boots Splits cuts or breaks in the ignition wires and insulation Inspect all vacuum hoses for Correct routing Refer to vehicle service manual or Vehicle Emis sion Control Information VECI decal located in the engine com partment Pinches and kinks Splits cuts or breaks e Inspect wiring for Contact with sharp edges Contact with hot surfaces such as exhaust manifolds Pinched burned or chafed insula tion Proper routing and connections e Check electrical connectors for Corrosion on pins Bent or damaged pins Contacts not properly seated in housing Bad wire crimps to terminals Section 1 Multimeter Basic Functions Digital multimeters or DMMs have many special features and functions This section defines these features
38. pro speed RPM between 1800 and vides power to the rest of the vehicles 2800 RPM electrical systems lights fan radio etc Hold this speed through Step 11 Test Procedure see Fig 23 Have an assistance help hold speed Insert BLACK test lead into COM test lead jack Insert RED test lead into ACV Q test lead jack Connect RED test lead to positive terminal of battery Connect BLACK test lead to nega tive terminal of battery Turn multimeter rotary switch to 20V DC range 6 Start engine Let idle Turn off all accessories and view reading on display Charging system is normal if dis play reads 13 2 to 15 2 volts e If display voltage is not between 13 2 to 15 2 volts then proceed to Step 13 9 View reading on display Voltage reading should not change from Step 7 by more than 0 5V 10 Load the electrical system by turn ing on the lights windshield wip ers and setting the blower fan on high 11 View reading on display Voltage should not drop down below about 13 0V 12 Shut off all accessories return engine to curb idle and shut off 13 Test Results If voltage readings in Steps 7 9 and 11 were as expected then charging system is normal If any voltage readings in Steps 7 9 and 11 were different then shown here or in vehicle service manual then check for a loose alternator belt defective regulator or alterna tor poor
39. res CAUTION Some vehicles are equipped with safety air bags You must follow vehicle service manual cautions when working around the air bag components or wiring If the cautions are not followed the air bag may open up unexpectedly resulting in personal injury Note that the air bag can still open up several minutes after the ignition key is off or even if the vehicle battery is disconnected because of a special energy reserve module All information illustrations and specifications contained in this manual are based on the latest information available from industry sources at the time of publication No warranty expressed or implied can be made for its accuracy or completeness nor is any responsibility assumed by Actron Manufacturing Co or anyone connected with it for loss or damages suffered through reliance on any information contained in this manual or misuse of accompanying product Actron Manufacturing Co reserves the right to make changes at any time to this manual or accompa nying product without obligation to notify any person or organization of such changes Vehicle Service Manual Sources For Service Information The following is a list of sources to obtain vehicle service information for your specific vehicle e Contact your local Automotive Dealership Parts Department e Contact local retail auto parts stores for aftermarket vehicle service information e Contact your local library Libraries often all
40. s EGR valve position sensors and vane air flow sensors Test Procedure see Fig 33 e If multimeter overranges on larg est range then sensor is an open circuit and is defective Move RED test lead to sensor SIG NAL pin e Refer to vehicle service manual for location of sensor SIGNAL pin Operate Sensor Throttle Position Sensor Fig 33 Typical Toyota Throttle g Position Sensor SIGNAL IDLE SWITCH e Slowly move throttle linkage from closed to wide open posi tion Depending on hook up the dis play reading will either increase or decrease in resistance e The display reading should ei ther start at or end at the ap proximate resistance value measured in Step 6 Some throttle position sensors have an Idle or Wide Open Throttle WOT switch in addi 1 Insert BLACK test lead into COM test lead jack 2 Insert RED test lead into AV Q test lead jack 3 Disconnect wiring harness from sensor 4 Connect Test Leads Connect RED test lead to sensor POWER pin Connect BLACK test lead to sen sor GROUND pin e Refer to vehicle service manual for location of sensor POWER and GROUND pins 5 Turn multimeter rotary switch to 20KQ range 6 View and record reading on dis play Display should read some resis tance value e If multimeter is overranging adjust the range accordingly tion to a potentiometer e To test these switches follow the Testin
41. t leads across component where you want to measure resistance When making resistance measure ments polarity is not important The test leads just have to be connected across the component 6 Turn multimeter rotary switch to desired OHM range If the approximate resistance is un known start at the largest OHM range and decrease to the appropri ate range as required See Setting the Range on page 6 7 View reading on display Note range setting for correct units NOTE 2KQ 2 000Q 2MQ 2 000 0002 If you want to make precise resis tance measurements then subtract the test lead resistance found in Step 4 above from the display reading in Step 7 It is a good idea to do this for resistance measurements less than 10Q Measuring DC Current This multimeter can be used to measure DC current in the range from 0 to 10A If the current you are measuring exceeds 10A the internal fuse will blow see Fuse Replacement on page 7 Unlike voltage and resistance measurements where the multimeter is connected across the com ponent you are testing current measure ments must be made with the multimeter in series with the component Isolating current drains and short circuits are some DC Current applications To measure DC Current see Figs 10 amp 11 1 Insert BLACK test lead into COM test lead jack 2 Insert RED test lead into 10A test lead jack or mA test lead jack 3 Disconnect or electrically op
42. t possible range without overranging EXAMPLE Measuring an unknown re sistance Let s assume the multimeter is con nected to an engine coolant sensor with unknown resistance See Fig 3 Fig 3 actron en f M FU LAs i Start by setting the multimeter to the largest OHM range The display reads 0 0Q or a short circuit This sensor can t be shorted so reduce the range setting until you get a value of resistance At the 200KQ range the multimeter mea sured a value of 4 0 This means there is 4KQ of resistance across the engine coolant sensor terminals See Fig 4 If we change the multimeter to the 20KQ range See Fig 5 the display shows a Fig 4 value of 3 87KQ The actual value of resistance is 3 87KQand not 4KQ that was measured in the 200KQ range This is very important because if the manufacturer specifications say that the sensor should read 3 8 3 9KQ at 70 F then on the 200KQ range the sensor would be defective but at the 20KQ range it would test good Now set the multimeter to the 2KQ range See Fig 6 The display will indi Fig 6 cate an overrange con dition because 3 87KQis larger than 2KQ This example shows that by decreasing the range you in crease the ac curacy of your measurement When you change the range you change the lo cation of the decimal p
43. tive battery cable NOTE Do not start vehicle during this test because multimeter damage may result 7 Turn multimeter rotary switch to 10A DC or 200 mA position 8 View reading on display e Typical current draw is 100mA 1mA 0 001A e Refer to vehicle service manual for manufacturers specific Engine Off Battery Current Draw NOTE Radio station presets and clocks are accounted for in the 100mA typical current draw 9 Test Results Normal Current Draw Display read ing in Step 8 is within manufacturers specifications Excessive Current Draw Display reading in Step 8 is well out side manufacturers specifications Remove Fuses from fuse box one at a time until source of excessive current draw is located Non Fused circuits such as head lights relays and solenoids should also be checked as possible cur rent drains on battery When source of excessive current drain is found service as necessary Cranking Voltage Battery Load Test This test checks the battery to see if it is delivering enough voltage to the starter motor under cranking conditions Test Procedure see Fig 21 1 Disable ignition system so vehicle won t start Disconnect the primary of the igni tion coil or the distributor pick up coil or the cam crank sensor to disable the ignition system Refer to vehicle service manual for disabling proce dure 2 Insert BLACK test lead into COM test
44. ustrations for POWER and GROUND pin locations e For sensors not illustrated refer to vehicle service manual for pin lo cations 3 Insert BLACK test lead into COM test lead jack 4 Insert RED test lead into ACV Q gt test lead jack 5 Connect RED test lead to sensor SIGNAL pin 6 Connect BLACK test lead to 9V battery negative pin 7 Turn multimeter rotary switch to function Multimeter should sound a tone 8 Slide a flat blade of iron or mag netic steel between sensor and magnet Use a scrap of sheet metal knife blade steel ruler etc e Multimeter tone should stop and display should overrange e Remove steel blade and multim eter should again sound a tone Itis O K if display changes errati cally after metal blade is removed Repeat several times to verify re sults 9 Test Results Good Sensor Multimeter toggles from tone to overrange as steel blade is inserted and removed Bad Sensor No change in multim eter as steel blade is inserted and removed Chrysler Distributor Hall Effect POWER Jumper Wires GROUND SIGNAL Iron or Steel Blade Ford Distributor Q Hall Effect Magnet Typical Hall Effect Sensor SIGNAL GROUND POWER Magnetic Pick Up Coils Reluctance Sensors Reluctance sensors are used whenever the vehicle computer needs to know speed and position of a rotating object Reluctance sensors are commonly used in
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