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Idle Air Control (IAC) Motor

WARNING: This page is about a different car, the 1994 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Disconnect harness connector to motor. Check resistance across IAC coil terminals "A" and "B" (coil "B") and "C" and "D" (coil "A"). See Fig 1 . Resistance should be 40-80 ohms. If resistance is as specified, go to next step. If resistance is not as specified, replace IAC motor.
  2. 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).
Fig 1: IAC Motor Circuit (Eldorado)
G91E07428Courtesy of GENERAL MOTORS CORP.