P0602 — Control Module Programming Error

What it means

The control module reports that its programming or configuration is incomplete: required variant coding, immobiliser data or vehicle parameters such as tyre size, gearbox type or injector correction values are missing or invalid. Unlike a checksum error the memory itself is intact, the data simply was never written correctly. In practice the code appears after fitting a replacement ECU or after an aborted coding session, and the engine often will not start.

Likely causes (most common first)

1. Replacement or used ECU installed without coding and adaptation to the vehicle
2. Programming session aborted by a low battery, a lost diagnostic link or a closed door
3. Wrong software version or calibration for the engine, gearbox or market
4. Immobiliser data not matched between the ECU, the key and the body module
5. Injector or throttle adaptation values not written after component replacement
6. Faulty diagnostic interface or unstable supply during flashing

Can you drive with it?

Usually the engine will not start or runs only in limp mode, so the module must be programmed and coded before driving.