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

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. If equipped with an automatic transmission, the PCM will receive a signal from the Transmission Control Module (TCM) that the transmission is in PARK or NEUTRAL through circuit CET21 (GN/WH). If equipped with a manual transmission, the PCM will receive a signal from the Clutch Pedal Position (CPP) switch through circuit CET21 (GN/WH). 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.

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 BATTERIES


- Check the condition and charge of the batteries. Refer to Battery.
- Are the batteries 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 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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