Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Ignition Control Module
Check ignition coil, ECM/PCM and high-tension lead connections. Check secondary coil winding and high-tension lead resistance. Measure voltage between ground and appropriate ECM/PCM terminals. See ECM/PCM TERMINAL IDENTIFICATION table. If all measurements are within specification, and misfire still occurs, replace distributor or ignition coil.
| ECM/PCM Wire Color (1) | Closed Throttle Volts | WOT Volts | ||
|---|---|---|---|---|
| Red/White (3B) | Less Than 1 | 1-2 | ||
| White (4F) | 0 Or 5 | 2 | ||
| Yellow/Blue (4G) | 0 Or 5 | 1.5 | ||
| Brown/Yellow (4N) | Less Than 1 | .2 | ||
| Brown (4R) | Less Than 1 | .2 | ||
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Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.