Idle Air Control Motor (Stepper Motor) Check

Required Special Tool:
MD998463: Test Harness

Checking the Operation Sound

NOTE: Disconnecting the engine coolant temperature sensor connector and connecting the harness-side of the connector to another engine coolant temperature sensor that is at 20°C (68°F) or below is okay for this test.

1. Check that the engine coolant temperature is 20°C (68°F) or below.
2. Check that the operation sound of the stepper motor can be heard after the ignition is switched ON. (but without starting the motor.)
3. If the operation sound cannot be heard, check the stepper motor's activation circuit.
If the circuit is normal, it is probable that there is a malfunction of the stepper motor or engine control module.

Checking the Coil Resistance
1. Disconnect the idle air control motor connector and connect the test harness special tool MD998463.




2. Measure resistance between terminal 2 (white clip of the special tool) and either terminal 1 (red clip) or terminal 3 (blue clip) of the connector at the idle air control motor side.

Standard value: 28 - 33 ohms [at 20°C (68°F]

If resistance is not within the standard value, replace the IAC motor.
3. Measure the resistance between terminal 5 (green clip of the special tool) and either terminal 6 (yellow clip) or terminal 4 (black clip) of the connector at the idle air control motor side.

Standard value: 28 - 33 ohms [at 20°C (68°F]

If resistance is not within the standard value, replace the IAC motor.