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.

Engine Control Module: Testing and Inspection

This is the exact OEM manual section for the path above. Use the breadcrumb to move up or down the tree until you reach the precise year, make, model, and subsystem you need.

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Confident verification of a DTC repair can only be done by matching the test descriptions of the DTC and ensuring that the DTC RUNS and PASSES. To know if a test runs and passes use the scan tool and select DTC Status and note the DTC that needs verification. The status of the diagnostic test can be now observed. For symptom repairs, drive the vehicle and ensure the symptom is gone. Some system diagnostic tests can be performed using the Service Bay Test function of the scan tool. A Service Bay Test will allow a diagnostic test to run under static conditions such as in a service area.

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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.