Idle Speed Motor Position Sensor: Testing and Inspection

Idle Air Control Valve Position Sensor Circuit:

Engine Control Module Connector--For Pin Applications See Components:

TIP:
- The IAC valve position sensor is the most important sensor for controlling the idle speed.
- If a malfunction develops when the engine is idling and the engine load is varied by turning the A/C ON and OFF etc., this sensor is probably defective.

HARNESS TEST
1. Disconnect the ISC connector and turn the key to the ON position.

2. Using a Voltmeter, measure the power supply Voltage between the harness connector terminals 2 and ground and 4 and ground.

Voltage: 4.8 - 5.2 V

3. Check for continuity of the ground circuit, between the harness connector terminal 3 and ground.

Continuity: Should exist

5. Check for continuity between ECM harness connector terminals 5, 18 and 61 and ground.

Continuity: Should NOT exist

5. Check for continuity between ECM harness connector terminals 5, 18 and 61 and the corresponding sensor harness connector terminals.

Continuity: Should exist

If any of the previous tests produce unsatisfactory results, the harness will need to be repaired or replaced. Once repairs have been completed, clear the trouble codes and road test the vehicle to confirm that the repair has corrected the problem and the code doesn't return.

If the same trouble code reoccurs, it is possible that there is an intermittent failure of the component or the ECU. Check for looseness at all harness junctions and test for an intermittent failure.