U3001
Control Module Improper Shutdown Performance
The control module did not complete its shutdown sequence cleanly — power was lost before housekeeping (saving learned values, freeze frames, adaptations) finished.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Common causes
Ordered by how often each turns out to be the cause.
- Power supply lost before shutdown completedCommon
- Bad ground connectionPossible
- Gateway module routing CAN messages incorrectlyLess likely
Parts involved
- Control Module
- Module Power Supply
U3001 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.