System Description

BASIC OPERATION STRATEGY
The Idle Air Control motor responds to signals sent to it by the ECM. When idle speed is too low, the ECM commands the Idle Air Control motor to open a passageway to allow more air into the intake manifold. The unit varies its opening to raise or lower the amount of air bypassing the throttle plate.

TROUBLESHOOTING HINTS
If the number of stepper motor steps increases to 100-120 steps or decreases to 0 step, the cause is probably a malfunction of the stepper motor or damaged or disconnected wiring of the harness.

If the number of stepper motor steps is outside the standard value even through the results of the checking of the harness of the idle air control motor and of the component itself indicate no abnormal condition, the cause is probably one of the following:

- Incorrect adjustment of the standard idling speed
- Deposits adhering to the throttle valve
- Air drawn into the intake manifold from a leaking gasket, etc.
- Incomplete combustion inside a cylinder (Malfunction of spark plugs, ignition coil, injectors, compression pressure, etc.)

NOTE: When the vehicle is new [driven approximately 500 km (300 miles) or less] the number of steps may be about 30 steps greater than the standard value indicated above.