P0602 means Control Module Programming Error. The engine computer has detected that its software is missing, corrupted or not programmed for the vehicle. It is a generic OBD-II code, so the definition is the same on any make, but the most likely cause varies by engine; confirm with a scan tool and the service information for your vehicle before buying parts.
What P0602 means
Modern vehicles have many control modules that share information over a network, usually called the CAN bus. Codes starting with U mean a module has stopped hearing another one, and voltage and processor codes mean a module is not getting clean power or has an internal fault. Low battery voltage, poor grounds, blown fuses and damaged wiring cause many of these codes, so test the battery and charging system first.
P0602 symptoms
- Check engine light
- No start on some vehicles
- Poor running on some vehicles
Common causes of P0602
- Incomplete or interrupted programming
- Replacement module not programmed
- Internal module fault
How to diagnose P0602
- Check for software updates for the vehicle
- Reprogram the module with the correct software
- Check battery voltage during programming
Can you drive with P0602?
It depends on how the engine runs; have it reprogrammed promptly.
P0602 tips
Keep a battery maintainer connected while reprogramming; a voltage dip during programming is a common cause of this code.
Will P0602 clear itself?
If the fault stops, the computer turns off the check engine light by itself after several drive cycles without seeing it again, and the code stays in memory as history for a while. Clearing P0602 with a scan tool after a repair is fine, but if the cause is still there the code returns, sometimes within one drive. Disconnecting the battery also clears codes on most vehicles, but it erases learned fuel trims and idle settings as well.
Related codes
| Code | Meaning |
|---|---|
| P0601 | Internal Control Module Memory Check Sum Error |
| P0603 | Internal Control Module Keep Alive Memory (KAM) Error |
| P0606 | Control Module Processor |
Guides that help
When it is more than a sensor
Voltage and network codes come from wiring, the battery, the charging system or a module, not from engine or transmission wear. If a lost-communication code has left the transmission in limp mode, rule out the module and wiring before deciding the unit has failed, and see our transmissions only if testing confirms internal damage.
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