Repair & Diagnosis
- Check air induction system for leaks. Repair as necessary. If air induction system is okay, go to next step.
- Ensure ignition is off. Access ECM behind bottom center of instrument panel, in front of console. Disconnect ECM E4 connector. Turn ignition on. Using DVOM, measure voltage between ground and terminals No. 9 (Black/Yellow wire) and No. 10 (Black/Blue wire) at ECM E4 connector. See Figure. If both readings are 9-14 volts, go to step 4). If any reading is not 9-14 volts, go to next step.
- Turn ignition off. Disconnect IAC valve connector. IAC valve is located in front of throttle body at 6 o'clock position. Using ohmmeter, measure resistance between terminal No. 2 and terminals No. 1 and 3 at IAC valve. See Fig 1. If resistance is not 17-25 ohms (cold) and 22-29 ohms (hot), replace IAC valve. If resistance is 17-25 ohms (cold) and 22-29 ohms (hot), check for open or short circuit in wiring harness between IAC valve and ECM. See appropriate wiring diagram in WIRING DIAGRAMS
article. Repair wiring as necessary.
- Check IAC valve operation. See SYSTEM/COMPONENT TESTS
article. Replace IAC valve as necessary. If valve is okay, replace ECM and retest.
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