ECM internal timer for engine-off soak time malfunction — affects EVAP and O2 monitor scheduling.
Common symptoms
- Monitors not ready
- Intermittent no-start after soak
- Check engine light
Typical causes
- ECM software issue
- Low battery voltage corrupting keep-alive memory
- Failed ECM internal clock
What scanner do you need?
Full-system scanner (engine, ABS, SRS, transmission, service resets)
Use live data and freeze frame to confirm the fault before replacing parts. ABS, SRS, and network U-codes usually require a full-system scanner.
Diagnostic tips
- Record freeze frame data when the code first sets
- Clear the code only after fixing the root cause
- Check for related pending codes that point to a common issue
- Verify battery voltage is above 12.4V before chasing sensor codes