Pinpoint Test A: The Engine Does Not Crank
Starting System
Pinpoint Tests
Pinpoint Test A: The Engine Does Not Crank
Refer to Wiring Diagram Set 20, Starting System for schematic and connector information. Diagrams By Number
Normal Operation - Automatic Transmission
Under normal operation of an automatic transmission equipped vehicle, when the ignition switch is turned to the START position and released, the PCM receives a starter motor request signal through circuit CDC35 (BU/WH), power is then supplied to the starter relay through circuit CDC38 (WH/VT) from the PCM. The PCM will receive a signal from the digital Transmission Range (TR) sensor that the vehicle is in PARK or NEUTRAL through circuit CET22 (GY/BN). A ground is supplied through circuit CDC12 (YE) from the PCM causing the starter relay coil to energize and the relay contacts close. This allows power to be supplied from Battery Junction Box (BJB) fuse 40 (30A) to the relay contacts which then flows through circuit CDC25 (BN/GN) to the starter solenoid. The solenoid is grounded at the starter motor. Energizing the starter solenoid will engage the starter drive into the ring gear and closes the solenoid contacts allowing power directly from the battery through circuit SDC02 (RD) to the starter motor to start the engine. The PCM will disengage the starter motor based on engine running (rpm threshold), a set crank time has been exceeded or the ignition switch has been turned to the OFF position.
Normal Operation - Manual Transmission
Under normal operation of a manual transmission equipped vehicle, when the ignition switch is turned to the START position and held, the PCM receives a starter motor request signal through circuit CDC35 (BU/WH), power is then supplied to the starter relay through circuit CDC38 (WH/VT) from the PCM. The PCM will receive a signal from the Clutch Pedal Position (CPP) switch through circuit CE903 (BU/OG) when the clutch pedal is fully depressed. A ground is supplied through circuit CDC12 (YE) from the PCM causing the starter relay coil to energize and the relay contacts close. This allows power to be supplied from BJB fuse 40 (30A) to the relay contacts which then flows through circuit CDC25 (BN/GN) to the starter solenoid. The solenoid is grounded at the starter motor. Energizing the starter solenoid will engage the starter drive into the ring gear and closes the solenoid contacts allowing power directly from the battery through circuit SDC02 (RD) to the starter motor to start the engine. The PCM will disengage the starter motor when the ignition switch has been returned to the RUN position.
This pinpoint test is intended to diagnose the following:
- Anti-theft system
- Battery
- Circuitry
- CPP switch - manual transmission
- Ignition switch
- PCM
- Start diode
- Starter motor
- Starter motor relay
- Digital TR sensor - automatic transmission
PINPOINT TEST A: THE ENGINE DOES NOT CRANK
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A1 CHECK THE BATTERY
- Check the battery condition and charge. Refer to Battery.
- Is the battery OK?
Yes
GO to A2.
No
CHARGE or INSTALL a new battery as necessary. REFER to Battery. TEST the system for normal operation.
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A2 CHECK THE PATS AND PCM FOR DTCs
- Using the DTCs retrieved during Inspection and Verification, check for Passive Anti-Theft System (PATS) and PCM DTCs.
- Were any PATS and PCM DTCs retrieved?
Yes
REFER to Antitheft and Alarm Systems to diagnose the PATS DTCs. REFER to Computers and Control Systems Information to diagnose the PCM DTCs.
No
For automatic transmission equipped vehicles, GO to A3. For manual transmission equipped vehicles, GO to A4.
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A3 CHECK THE PCM TR SENSOR PID
- Enter the following diagnostic mode on the scan tool: Datalogger - PCM.
- While observing the TR sensor PID, place the vehicle in PARK and NEUTRAL.
- Does the PID match the gear selection?
Yes
GO to A5.
No
GO to the appropriate automatic transmission system to diagnose the TR sensor.
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A4 CHECK THE PCM STARTER MOTOR RELAY ENABLE (STRT_RLY) PID
- Enter the following diagnostic mode on the scan tool: DataLogger - PCM.
- Monitor the STRT_RLY PID while fully depressing the clutch pedal.
- Does the PID change from DISABLED to ENABLED?
Yes
GO to A5.
No
GO to A19.
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A5 CHECK THE BATTERY GROUND CABLE
- Measure the voltage between the positive battery post and the battery ground cable connection at the engine.
- Is the voltage greater than 10 volts?
Yes
GO to A6.
No
INSTALL a new battery ground cable. REFER to Battery. TEST the system for normal operation.
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A6 CHECK THE STARTER MOTOR GROUND
- Measure the voltage between the positive battery post and the starter motor case.
- Is the voltage greater than 10 volts?
Yes
GO to A7.
No
CLEAN the starter motor mounting flange and make sure the starter motor is correctly mounted. TEST the system for normal operation.
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A7 CHECK THE POWER SUPPLY TO THE STARTER MOTOR
- Measure the voltage between starter motor C3005-1, circuit 2037 (RD) and ground.
- Is the voltage greater than 10 volts?
Yes
GO to A8.
No
INSTALL a new positive battery cable. REFER to Battery. TEST the system for normal operation.
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A8 MANUALLY JUMP THE STARTER MOTOR
- Connect one end of a fused jumper wire to starter motor solenoid C197B-1, circuit CDC25 (BN/GN). Momentarily connect the other end of the jumper to starter motor C197A-1, circuit SDC02 (RD).
- Did the starter motor engage and the engine crank?
Yes
GO to A9.
No
INSTALL a new starter motor. REFER to Starter Motor Service and Repair. TEST the system for normal operation.
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A9 CHECK FOR START INPUT AT THE STARTER
- Disconnect: Starter Solenoid C197B.
- Measure the voltage between the starter motor solenoid C197B-1, circuit CDC25 (BN/GN) and ground, while holding the key in the START position.
- Is the voltage reading greater than 10 volts?
Yes
CLEAN the starter motor solenoid S-terminal and connector. CHECK the wiring and the starter motor for a loose or intermittent connection. TEST the system for normal operation.
No
GO to A10.
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A10 CHECK THE CIRCUIT TO THE STARTER MOTOR
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- Ignition OFF.
- Disconnect: Starter Motor Relay.
- Measure the resistance between starter motor C197B-1, circuit CDC25 (BN/GN) and Battery Junction Box (BJB) starter relay cavity 87, circuit CDC25 (BN/GN).
- Is the resistance less than 5 ohms?
Yes
GO to A11.
No
REPAIR the circuit CDC25 (BN/GN). TEST the system for normal operation.
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A11 CHECK FOR START INPUT AT THE STARTER MOTOR RELAY
- Measure the voltage between BJB starter motor relay cavity 85, circuit CDC38 (WH/VT) and ground, while holding the key in the START position.
- Is the voltage greater than 10 volts?
Yes
GO to A12.
No
GO to A14.
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A12 CHECK THE BATTERY SUPPLY TO THE STARTER RELAY
- Ignition OFF.
- Measure the voltage at starter motor relay cavity 30 and ground.
- Is the voltage reading greater than 10 volts?
Yes
GO to A13.
No
INSTALL a new BJB fuse 40 (30A). TEST the system for normal operation. If the fuse opens again, REFER to Wiring Diagrams to identify the possible causes of the circuit short. Diagrams By Number
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A13 CHECK FOR STARTER MOTOR RELAY GROUND
- Measure the voltage between BJB starter motor relay cavity 85, circuit CDC12 (YE) and cavity 86, circuit CDC38 (WH/VT), while holding the key in the START position.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new starter motor relay. TEST the system for normal operation.
No
GO to A18.
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A14 CHECK THE START DIODE
- Disconnect: Start Diode.
- Test the start diode for an open or shorted condition.
- Is the start diode open or shorted?
Yes
INSTALL a new start diode. TEST the system for normal operation.
No
GO to A15.
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A15 CHECK CIRCUIT CDC35 (BU/WH) FOR VOLTAGE AT THE START DIODE
- If equipped with an automatic transmission, make sure the vehicle is in PARK or NEUTRAL. If equipped with a manual transmission, fully depress the clutch pedal.
- Measure the voltage between BJB start diode C1-60 cavity-1, circuit CDC35 (BU/WH) and ground, while holding the key in the START position.
- Is the voltage greater than 10 volts?
Yes
REPAIR the circuit CDC38 (WH/VT). TEST the system for normal operation.
No
GO to A16.
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A16 CHECK CIRCUIT SBP27 (BU/RD) FOR VOLTAGE
- Disconnect: Ignition Switch C250.
- Measure the voltage between ignition switch C250-9, circuit SBP27 (BU/RD), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to A17.
No
REPAIR circuit SBP27 (BU/RD). TEST the system for normal operation.
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A17 CHECK THE IGNITION SWITCH
- Carry out the Ignition Switch Component Test.
- Did the ignition switch pass the component test?
Yes
REPAIR circuit CDC35 (BU/WH). TEST the system for normal operation.
No
INSTALL a new ignition switch. REFER to Steering Column. TEST the system for normal operation.
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A18 CHECK CIRCUIT CDC12 (YE) FOR AN OPEN
- Disconnect: PCM C175B.
- Measure the resistance between the starter motor relay cavity 86, circuit CDC12 (YE) and PCM C175B-2, circuit CDC12 (YE), harness side.
- Is the resistance reading 5 ohms?
Yes
DIAGNOSE the PCM. REFER to Computers and Control Systems Information.
No
REPAIR circuit CDC12 (YE) for an open. TEST the system for normal operation.
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A19 CHECK THE CPP SWITCH BOTTOM OF TRAVEL CIRCUIT
- Ignition OFF.
- Disconnect: PCM C175B.
- Measure the voltage between the battery positive post and PCM connector C175B-34, circuit CE903 (BU/OG), harness side, with the clutch pedal fully depressed.
- Is the voltage greater than 10 volts?
Yes
GO to A20.
No
GO to A21.
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A20 CHECK THE CPP SWITCH TOP OF TRAVEL CIRCUIT
- Measure the voltage between the battery positive post and PCM connector C175B-32, circuit CE904 (GN/VT), harness side.
- Is the voltage greater than 10 volts?
Yes
DIAGNOSE the PCM. REFER to Computers and Control Systems Information.
No
GO to A21.
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A21 CHECK THE CPP SWITCH GROUND CIRCUIT FOR AN OPEN
- Disconnect: CPP Switch C257.
- Measure the voltage between battery positive post and CPP switch C257-6, GD113 (BK/YE), harness side and voltage between battery positive post and CPP switch C257-3, GD113 (BK/YE), harness side.
- Are the voltages greater than 10 volts?
Yes
GO to A22.
No
REPAIR circuit GD113 (BK/YE) for an open. TEST the system for normal operation.
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A22 CHECK THE CPP SWITCH BOTTOM TRAVEL CIRCUIT FOR AN OPEN
- Measure the resistance between PCM C175B, harness side and CPP switch C257, harness side using the following chart:
- Are the resistances 5 ohms or less?
Yes
INSTALL a new CPP switch. TEST the system for normal operation.
No
REPAIR circuit CE904 (GN/VT) or CE903 (BU/OG) for an open. TEST the system for normal operation.
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