Control Module Power Off Timer Performance
The internal power-down timer of the engine controller does not run as expected. The module either stays awake too long after key-off (battery drain) or shuts down too early (no aftertreatment cool-down or learn-write).
Affected components
- Control module
- Main relay
Common causes
- Medium likelihood: Intermittent main relay opens early
- Medium likelihood: Software timer counter corrupted
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.