ECM or PCM Power Relay De-Energized Performance Too Early
The main power relay drops out earlier than the calibrated post-run window allows. The ECU loses power before completing housekeeping (e.g. saving adaptions, parking the throttle), which causes adaptive learning to reset.
Affected components
- Ecm power relay
Common causes
- High likelihood: Relay coil weak - drops early
Possible symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
Diagnostic notes
- The malfunction indicator lamp may illuminate
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.