25 Idle Air Control Motor Circuits - (P 0505)

25 IDLE AIR CONTROL MOTOR CIRCUITS - (P 0505)





The Idle Air Control (IAC) stepper motor is located on the throttle body. It is operated as a Powertrain Control Module (PCM) output through pins 14, 15, 34, and 35. The IAC is used to maintain engine RPM at idle, and as an off-idle load control (A/C compressor cycling). With the throttle plate completely closed, placing a load on the engine (A/C or power steering operation) might cause the engine to stall or run rough. As the PCM anticipates loads, it operates the IAC motor, opening the threatful bypass passage and allowing more air into the intake manifold. A malfunction of this system could cause rough idle and unstable emissions.

ENABLING CONDITIONS
- Battery voltage must be greater than 10 volts
- Ignition voltage must be applied to the PCM

A shorted or open condition in one of the motor circuits for three seconds causes this DTC to be stored and the MIL to be illuminated.

This malfunction could possibly be caused by problems with any of the following components:

- IAC motor
- IAC motor wiring or related connectors (open or short)
- PCM