Idle Air Control (IAC) Motor
- Disconnect harness connector to motor. Check resistance across IAC coil terminals "A" and "B" (B coil) and "C" and "D" (A coil). Resistance should be 40-80 ohms. See Fig 1 . If resistance is as specified, 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:
Additional testing of Idle Air Control (IAC) motor requires an IAC motor actuator and node light, or a "Scan" tester capable of cycling ECM output devices (General Motors Tech 1).