P0602 — Control Module Programming Error
Drivable short-term, but fix now to avoid damage.
What P0602 means
This code means the engine control module has a programming error, often because it wasn't flashed or programmed properly. It's commonly seen after a module replacement or software update that didn't complete correctly, but a corrupted memory or voltage drop during programming can cause it too. It's a serious code that's usually fixed by correctly reprogramming the module.
Common symptoms
- Check engine light is on
- Engine runs poorly, stalls, or won't start
- Vehicle in limp or reduced power mode
- Issue appears after a module replacement or update
- Other systems may behave erratically
Common causes
- Incomplete or incorrect module programming
- Failed software update or flash
- Voltage drop during programming
- Corrupted module memory
- Faulty engine control module
Typical repair cost
$150 – $1200
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0602 code?
Often not reliably. A programming error can leave the engine running poorly or not starting, so the car may be undrivable until the module is correctly programmed.
How much does it cost to fix a P0602 code?
It ranges from about $150 for reprogramming to $1,200 or more if the module must be replaced and then programmed at a dealer or specialist.
Is a P0602 code serious?
Yes. It signals the engine computer isn't programmed correctly, which can prevent the vehicle from running properly, so it needs prompt attention.
What usually causes a P0602 code?
It's most often caused by a module that wasn't programmed correctly, frequently after a replacement or a software flash that didn't complete due to a voltage drop or interruption.