Component Tests

SYSTEM OPERATI0N

Idle Air Control (IAC) Valve:

Air Valve

NOTE: Start this check with engine cold (coolant temperature below 68°F, 20°C).

1. Connect Super STAR tester II to data link connector.

2. Set test switch to SELF TEST.

3. Start engine and verify that rpm gradually decreases as engine warms up.

IAC Valve

1. Warm up engine.

2. Check if a click sound is heard and engine speed increases to approximately 1200 rpm when IAC valve connector is unplugged at idle.

3. If engine speed does not change, replace IAC valve.

IAC Valve Resistance

Idle Speed Control (ISC) Valve Testing:

1. Unplug IAC valve connector.

2. Check resistance across valve terminals. It should be 11-13 ohms at 20°C (68°F).

3. If not as specified, replace IAC valve.

Air Valve Inspection

1. Remove air valve.

2. Cool valve to below 32°F (0°C).

Bypass Air Valve:

3. Heat valve at A using a drier and verify that part B moves in direction of C in the image.