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.
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Chart :
- The MIL ("Check Engine lamp") should be "ON" steady with the ignition "ON" and the engine "OFF". If not, the "No MIL" chart should be used to isolate the malfunction.
- The RPL ("Reduced Power lamp") should be "ON" (only 3 second) steady with the ignition "ON" and the engine "OFF". If not, the "No RPL "chart should be used to isolate the malfunction.
- This test ensures that the ECM is capable of controlling the MIL ("Check Engine lamp") and the MIL ("Check Engine lamp") driver circuit is not shorted to ground.
- This test ensures that the ECM is capable of controlling the RPL ("Reduced Power lamp") and the RPL ("Reduced Power lamp") driver circuit is not shorted to ground.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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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