What are the common causes of P0602?

A PCM calibration that did not load correctly. The wrong software flashed for the vehicle. A weak battery during a reflash. A failed PCM. A wiring or ground fault at the PCM.

Check for other codes that point to a module fault. Check battery voltage and grounds at the PCM. Inspect PCM connectors for corrosion or damage. Reflash the PCM with the correct calibration for the VIN. Replace the PCM if it will not accept a flash. Clear the code and retest.

P0602

Control Module Programming Error

System: Computer output circuits (P code)
Lamp: Check Engine Light
Category: Powertrain - Computer and Auxiliary Controls

What it means

P0602 means Control Module Programming Error.

Where it lives

For P0602, the description names the module as the part involved.

Check these first

A PCM calibration that did not load correctly
The wrong software flashed for the vehicle
A weak battery during a reflash
A failed PCM
A wiring or ground fault at the PCM

What to do next

Check for other codes that point to a module fault
Check battery voltage and grounds at the PCM
Inspect PCM connectors for corrosion or damage
Reflash the PCM with the correct calibration for the VIN
Replace the PCM if it will not accept a flash
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.