Protege & Protege5
- Resistance Inspection
Disconnect Idle Air Control (IAC) valve 2-pin harness connector. See IAC VALVE LOCATION table. Using an ohmmeter, measure resistance between IAC valve terminals. See IAC VALVE RESISTANCE SPECIFICATIONS table. If IAC valve is okay, check for open or short circuit. Go to next step. If resistance reading is not within specification, replace IAC valve. - Open Circuit Inspection
Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Check for continuity between following terminals:- Power circuit - IAC valve harness connector terminal "A" (Brown wire) and breakout box terminal No. 54.
- GND circuit - IAC valve harness connector terminal "B" (Gray wire) and breakout box terminal No. 83.
If continuity is present, go to next step. If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
- Short Circuit Inspection
- Power circuit - IAC valve harness connector terminal "A" and breakout box terminal No. 54 (Brown wire) to ground.
- GND circuit - IAC valve harness connector terminal "B" and breakout box terminal No. 83 (Gray wire) to ground.
If continuity is present, repair short circuit in suspect wire or replace wire harness.