Idle Air Control (IAC) Valve
- Disconnect harness connector to motor. Check resistance across IAC coil terminals "A" to "B" and "C" to "D". See Fig 1 . Resistance should be 40-80 ohms. If okay, go to next step. If resistance is not as specified, replace IAC valve.
- Check resistance between IAC terminals "B" to "C" and "A" to "D". Resistance should be infinite. If resistance is not as specified, replace IAC valve.
NOTE:
Functional testing of Idle Air Control (IAC) valve requires a bidirectional scan tool capable of cycling PCM/VCM output devices or a special IAC Driver and Noid Light Set (222L or J-37027). Text in TESTS W/CODES
article may refer to Tech 1 tester, General Motor's bidirectional scan tool.