Test C: The Engine Cranks Slowly

PINPOINT TEST C: THE ENGINE CRANKS SLOWLY

C1-C2:

C2-C3:

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 (SMR) 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 (SMR) 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
- Ground circuit
- Starter motor