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.
1993 Pontiac LeMans VLFACTORY OEM SERVICE PROCEDURE
ECM Ground Circuit
- Measure resistance between ECM terminal A12 (Black/White wire) and ground. ECM is located behind passenger kick panel. Ground for ECM is located on right side of engine (firewall side). See Figure . Resistance should be zero ohms. If resistance is not zero ohms, repair open in ground circuit.
- Connect negative lead of DVOM to ground. Start engine. Backprobe terminals A12 and D1. DVOM should indicate less than one volt. If reading is greater than one volt, check for open, corrosion, or loose connection on ground wire.
Factory Service Tools
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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.