Electronic Air Control (EAC) Solenoid
- Turn ignition on, engine off. Disconnect EAC solenoid connector. Connect test light between solenoid connector terminals. See Fig 1. If test light comes on, check for grounded wire from solenoid to ECM. If wire is not grounded, replace ECM. If test light did not turn on, go to next step.
- Ground ALDL diagnostic connector. If test light comes on, check for faulty EAC solenoid connector. If connector is okay, replace EAC valve. If test light did not turn on, connect test light between harness terminal "A" to ground. See Fig 1. If test light still did not turn on, check for open in fuse or wire to ignition.
- If test light came on, check for open in wire from solenoid to ECM. If wire is okay, check EAC solenoid resistance. If resistance is less than 20 ohms, replace EAC solenoid and perform ECM quad-driver check. If EAC solenoid resistance is greater than 20 ohms, replace ECM only.
Courtesy of GENERAL MOTORS CORP.