P0602 Code: Control Module Programming Error
⚠️ Severe · drivable
May be undrivable or run poorly because the engine computer lacks the correct programming. Have it checked before driving far.
What P0602 means
The engine computer's programming doesn't match the vehicle, or the stored calibration is corrupt or missing. This can happen when a software update is interrupted, the wrong file is loaded, or the computer loses power during a flash.
Symptoms
- Check engine light is on
- Engine won't start or runs rough
- Reduced power or no-start condition
- Other modules losing communication
Common causes
- most common: Interrupted or failed software update
- common: Wrong calibration loaded for the vehicle
- common: Low battery during programming
- less common: Failing engine computer
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Recharge or replace a weak battery before reprogramming | Yes | $0–100 |
| Reflash the engine computer with the correct calibration | Mechanic | $100–300 |
| Replace the engine computer | Mechanic | $400–1200 |
Frequently asked questions
Can I drive with a P0602 code?
Maybe, but the engine can run poorly or not start. It's safest to have the computer reprogrammed before driving far.
What causes a P0602 code?
Usually an interrupted or wrong software update. A dead battery during programming can also cause it.
How much does it cost to fix a P0602?
Reprogramming runs about $100–300. If the computer must be replaced, expect $400–1200.
Related codes
P0601
P0601 Code: Internal Control Module Memory Check Sum Error
P0603P0603 Code: Internal Control Module Keep Alive Memory (KAM) Error
P0606P0606 Code: ECM/PCM Processor Fault
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.