P0601
- Powertrain
- Generic (SAE)
Get it looked at now
Driving may cause further damage or leave you stranded. Arrange service promptly rather than waiting.
Internal Control Module Memory Check Sum Error
This code is in our catalogue but has not yet been through editorial review, so the guidance below is limited to what our structured data supports. We publish deeper diagnostic content only after a code has been reviewed — here is why.
The ECU's internal memory checksum does not match the expected value at startup — the firmware/calibration in flash has become corrupt. Often appears after a failed flash, low battery during programming, or genuine module hardware failure.
A trouble code records what a control module measured. It does not identify which part failed. Test before replacing anything.
- Safe to drive
- Driving may cause further damage or leave you stranded. Arrange service promptly rather than waiting.
- Urgency
- Get it looked at now
- Will it pass emissions
- Not affected
- Check engine light
- Solid
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
Many vehicles show no symptom at all beyond the warning light. The absence of a symptom does not mean the fault is not real.
| # | Cause | How often | Component |
|---|---|---|---|
| 1 | Failed flash / interrupted programming | Common | — |
| 2 | Module hardware failure | Common | — |
| 3 | Module software outdated, reflash may resolve | Occasional | — |
Ordering reflects how often each cause is responsible in general, not a probability for your vehicle. Confirm by testing.
- ECM
- Definition
- Generic code set (SAE J2012 / ISO 15031-6) via the OBDexopen database, dedicated to the public domain under CC0-1.0.
- Diagnostic guidance
- Written and reviewed in-house. See our editorial policy.
- Review status
- Awaiting review
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