Idle Air Control (IAC) Motor
- Disconnect harness connector to motor. Check resistance across IAC coil terminals "A" to "B" and "C" to "D". Resistance should be 40-80 ohms. See Fig 1. If okay, go to next step. If resistance is not as specified, replace IAC motor.
- Check resistance between IAC terminals "B" to "C" and "A" to "D". Resistance should be infinite. If resistance is not as specified, replace IAC motor.
NOTE:
Testing Idle Air Control (IAC) motor requires a "Scan" tester capable of cycling ECM output devices. Flow charts in the TESTS W/CODES articles may refer to the Tech 1 tester, General Motors' version of this tester.