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.
DTC P0602: ECM/PCM Programming Error
- Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
- This DTC is indicated when a ECM/PCM update is not completed.
- Do not turn the ignition switch OFF while updating the ECM/PCM. If you turn the ignition switch OFF before completion, the ECM/PCM can be damaged.
- Do the ECM/PCM update procedure (see UPDATING THE ECM/PCM ).
- Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0602 indicated?
YES - Replace the original ECM/PCM (see ECM/PCM REPLACEMENT
NO - Update is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.
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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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