Pinpoint Test C: The Engine Cranks Slowly
Starting System
Pinpoint Tests
Pinpoint Test C: The Engine Cranks Slowly
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:
- Battery
- Circuitry
- Starter motor
PINPOINT TEST C: THE ENGINE CRANKS SLOWLY
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C1 CHECK THE BATTERY
- Check the battery condition and charge. Refer to Battery.
- Is the battery OK?
Yes
GO to C2.
No
CHARGE or INSTALL a new battery as required. TEST the system for normal operation.
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C2 CHECK THE VOLTAGE TO THE STARTER
- Ignition OFF.
- Measure the voltage between starter motor solenoid positive terminal and ground.
- Is the voltage 10 volts or greater?
Yes
GO to C3.
No
REPAIR circuit 2037 (RD). CLEAN and TIGHTEN the connections at the battery terminals. TEST the system for normal operation.
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C3 CHECK MOTOR GROUND CIRCUIT
- Carry out the Motor Ground Circuit Test. Refer to the Component Tests. Component Tests and General Diagnostics
- Is the ground OK?
Yes
INSTALL a new starter motor. TEST the system for normal operation.
No
REPAIR the ground circuit as necessary. TEST the system for normal operation.
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