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
Under normal operation, 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 transmission that the vehicle is in PARK or NEUTRAL through circuit CET40 (GN/OG). 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 13 (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.
This pinpoint test is intended to diagnose the following:
- Anti-theft system
- Battery
- Circuitry
- Ignition switch
- PCM
- Park/Neutral Position (PNP) switch (integral to the mechatronics unit)
- Start diode
- Starter motor
- Starter motor relay
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, Mounting and Cables Testing and Inspection.
- Is the battery OK?
Yes
GO to A2.
No
CHARGE or INSTALL a new battery as necessary. REFER to Battery, Mounting and Cables Battery. TEST the system for normal operation.
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A2 CHECK THE PCM FOR DTCs
- Check for PCM DTCs.
- Were any PCM DTCs retrieved?
Yes
If PCM DTC P1260 is retrieved, REFER to Anti-Theft - Passive Anti-Theft System (PATS) Testing and Inspection. All other PCM DTCs, REFER to Computers and Control Systems.
No
GO to A3.
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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 PCM TR sensor PID, place the vehicle in PARK and NEUTRAL.
- Does the PID match the gear selection?
Yes
GO to A4.
No
REFER to the Park Neutral Circuit Pinpoint Test to diagnose the transmission. REFER to Automatic Transaxle/Transmission - 6R80 Testing and Inspection.
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A4 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 A5.
No
INSTALL a new battery ground cable. REFER to Battery, Mounting and Cables Service and Repair. TEST the system for normal operation.
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A5 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 A6.
No
CLEAN the starter motor mounting flange and VERIFY the starter motor is correctly mounted. TEST the system for normal operation.
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A6 CHECK THE POWER SUPPLY TO THE STARTER MOTOR
- Measure the voltage between starter motor C197A-1, circuit SDC02 (RD) and ground.
- Is the voltage greater than 10 volts?
Yes
GO to A7.
No
INSTALL a new positive battery cable. REFER to Battery, Mounting and Cables Service and Repair. TEST the system for normal operation.
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A7 MANUALLY JUMP THE STARTER MOTOR
- Connect one end of a fused jumper wire to starter motor solenoid terminal C197A-1, circuit SDC02 (RD). Momentarily connect the other end of the jumper to starter motor solenoid terminal C197B-1, circuit CDC25 (BN/GN).
- Did the starter motor engage and the engine crank?
Yes
GO to A8.
No
INSTALL a new starter motor. REFER to Starter Motor Service and Repair. TEST the system for normal operation.
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A8 CHECK THE START INPUT TO THE STARTER MOTOR
- Disconnect: Starter S-Connector.
- Key in START position.
- Measure the voltage at the starter motor solenoid S-connector C197B-1, circuit CDC25 (BN/GN).
- 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 A9.
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A9 CHECK CIRCUIT CDC25 (BN/GN) FOR AN OPEN
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- Disconnect: Starter Solenoid S-Connector.
- Measure the resistance of circuit CDC25 (BN/GN) between starter relay pin cavity 5 and the starter solenoid S-connector C197B-1, circuit CDC25 (BN/GN).
- Is the resistance reading 5 ohms or less?
Yes
GO to A10.
No
REPAIR circuit CDC25 (BN/GN) for an open. TEST the system for normal operation.
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A10 CHECK FOR START INPUT AT THE STARTER MOTOR RELAY
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- Disconnect: Starter Motor Relay.
- Measure the voltage between starter motor relay pin cavity 1, circuit CDC38 (WH/VT) and ground with the ignition switch in the START position.
- Is the voltage greater than 10 volts?
Yes
GO to A11.
No
GO to A13.
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A11 CHECK THE BATTERY SUPPLY TO THE STARTER RELAY
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- Disconnect: Starter Motor Relay.
- Measure the voltage at starter motor relay pin cavity 3.
- Is the voltage reading greater than 10 volts?
Yes
GO to A12.
No
VERIFY the BJB fuse 13 (30A) is OK. If OK, REPAIR circuit SDC04 (RD). If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. Diagrams By Number
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A12 CHECK FOR STARTER MOTOR RELAY GROUND
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- Disconnect: Starter Motor Relay.
- Key in START position.
- Measure the voltage between starter motor relay pin cavity 1, circuit CDC38 (WH/VT) and pin cavity 2, circuit CDC12 (YE).
- Is the voltage greater than 10 volts?
Yes
INSTALL a new starter motor relay. TEST the system for normal operation.
No
GO to A20.
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A13 CHECK FOR VOLTAGE ON CIRCUIT CET40 (GN/OG) AT PCM CONNECTOR
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: PCM C175B.
- Ignition ON.
- Measure the voltage between PCM C175B-30, circuit CET40 (GN/OG), harness side and ground while moving the selector lever from PARK to NEUTRAL.
- Is the voltage greater than 10 volts with the selector lever in PARK and NEUTRAL?
Yes
GO to A16.
No
GO to A14.
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A14 CHECK CIRCUIT CET40 (GN/OG) FOR A SHORT TO GROUND
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- Measure the resistance between C175B-30, circuit CET40 (GN/OG), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to A15.
No
REPAIR circuit CET40 (GN/OG). TEST the system for normal operation.
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A15 CHECK CIRCUIT CET40 (GN/OG) FOR OPEN
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: Transmission C1548.
- Measure the resistance between PCM C175B-30, circuit CET40 (GN/OG), harness side and transmission C1548-10, circuit CET40 (GN/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
Replace the transmission mechatronics unit. REFER to Automatic Transaxle/Transmission - 6R80 Service and Repair. TEST the system for normal operation.
No
REPAIR circuit CET40 (GN/OG). TEST the system for normal operation.
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A16 CHECK THE START DIODE
- Disconnect: Start Diode.
- Check the start diode.
- Is the start diode open or shorted?
Yes
INSTALL a new start diode. TEST the system for normal operation.
No
GO to A17.
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A17 CHECK CIRCUIT CDC35 (BU/WH) FOR VOLTAGE AT THE START DIODE
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- Disconnect: Start Diode.
- Measure the voltage between start diode cavity C1-60-1, circuit CDC35 (BU/WH) and ground with the ignition switch in the START position.
- Is the voltage greater than 10 volts?
Yes
REPAIR circuit CDC38 (WH/VT). TEST the system for normal operation.
No
GO to A18.
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A18 CHECK CIRCUIT SBP27 (BU/RD) FOR VOLTAGE
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- 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 A19.
No
REPAIR circuit SBP27 (BU/RD). TEST the system for normal operation.
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A19 CHECK THE IGNITION SWITCH
- Carry out the Ignition Switch Component Test.
Refer to Wiring Diagrams for component testing. Diagrams By Number
- 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 Switches Ignition Switch. TEST the system for normal operation.
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A20 CHECK CIRCUIT CDC12 (YE) FOR AN OPEN
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- Disconnect: PCM C175B.
- Measure the resistance between the starter motor relay pin cavity 2, circuit CDC12 (YE) and PCM C175B-7, circuit CDC12 (YE).
- Is the resistance reading 5 ohms or less?
Yes
DIAGNOSE the PCM. REFER to Computers and Control Systems.
No
REPAIR circuit CDC12 (YE) for an open. TEST the system for normal operation.
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