Test C: Unusual Starter Noise
PINPOINT TEST C: UNUSUAL STARTER NOISENormal Operation
In normal operation, voltage from battery junction box (BJB) fuse 7 (60A) is supplied to the ignition switch through circuit 1050 (LG/VT). When the ignition switch is placed in the START position, voltage is supplied through circuit 0033 (WH/PK) to central junction box (CJB) fuse 33 (10A).
If equipped with a 4R70E/4R75E transmission, power is then supplied from the CJB fuse 33 (10A) to the digital transmission range (TR) sensor through circuit 1093 (TN/RD). With the vehicle in PARK or NEUTRAL, power is supplied to the starter relay through circuit 0032 (RD/LB).
If equipped with a 5R110 transmission, power is then supplied from the CJB fuse 33 (10A) to the starter relay through circuit 1093 (TN/RD).
The starter relay is supplied ground from the PCM through circuit 1419 (LG/YE). Power is supplied at all times to the starter motor from the battery, circuit 2037 (RD). The starter relay has voltage supplied at all times from BJB fuse 18 (60A), circuit 1523 (DG). When the starter relay is energized, voltage supplied to the starter relay is sent to the starter motor solenoid through circuit 0113 (YE/LB). The starter motor is disengaged when the key is released from the START position.
This pinpoint test is intended to diagnose the following:
- Starter mounting
- Starter motor
- Incorrect starter drive engagement
