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.
Chart A-1 - No Check Engine Light: Notes
There should always be a steady CHECK ENGINE light when ignition is on and engine stopped. Electronic Control Module (ECM) will also turn on light if ECM senses a malfunction or ECM fails.
- Test light provides a ground source to CHECK ENGINE light. If circuit is okay, CHECK ENGINE light should be on when circuit No. A5 is probed.
- Battery voltage at circuits No. B1 and C16 is protected by a 30-amp fusible link in relay center under hood near battery. If circuits No. B1 and C16 have voltage, ECM grounds or ECM are faulty.
- Using a test light connected to 12 volts, probe each system ground circuit to ensure a good ground is present.
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.
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