Checking Idle Air Control Motor Operation

SYMPTOM
* CHECKING THE IDLE AIR CONTROL MOTOR

POSSIBLE CAUSES
- DRB unable to set engine speed
- IAC driver # 1 shorted to ground
- IAC driver # 2 shorted to ground
- IAC driver # 3 shorted to ground
- IAC driver # 4 shorted to ground
- IAC motor connector terminals observable defect
- PCM connector terminals observable defect
- Engine vacuum leaks
- Idle air control motor defective
- IAC driver circuits 2,3,4 shorted together
- IAC driver circuits 1,2,3,4 shorted together
- IAC driver circuits 3 and 4 shorted together