Test B: Unusual Starter Noise

PINPOINT TEST B: UNUSUAL STARTER NOISE

B1-B3:

Normal Operation
Under normal operation, constant power is supplied to the starter relay on circuit 16 (RD/LG). When the key is placed in the START position, with the vehicle in PARK or NEUTRAL, the TR sensor (automatic transmission) or with the clutch pedal depressed the clutch cutoff switch (manual transmission) provides power to the starter relay coil on circuit 1093 (TN/RD). The PCM provides ground to the starter relay coil on circuit 325 (DB/OG) through the starter relay diode and circuit 32 (RD/LB). When the coil of the relay is energized, it sends power to the starter motor on circuit 33 (WH/PK).

Possible causes
- Loose starter motor mounting bolts or brackets.
- Worn or damaged flywheel ring gear.
- Worn or damaged starter motor drive gear.