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 P1602: Pcm Not Programmed: Testing
Using scan tool, attempt to program PCM. Turn ignition on. Start engine. If engine will not start, crank engine for 15 seconds. Turn ignition off. Repeat at least once. If engine starts, allow it to reach normal operating temperature. Using scan tool, read DTCs. If DTC P1602 is displayed, replace PCM. If DTC P1602 is not displayed, test is complete.
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.