OBD-II diagnostic trouble code
P0601Caution
Internal Control Module Memory Check Sum Error
The engine computer runs a self-check on its own internal memory (where its programming and calibration data live) and found the data didn't pass a checksum validation — essentially, the ECU detected corruption in its own stored program data.
Symptoms
- Check engine light on, sometimes with no other symptom at all
- Occasionally erratic or inconsistent engine behavior if the corrupted data affects a specific function
- In rare cases, the engine may not start if critical calibration data is affected
Likely causes
- A voltage spike or drop (from a weak battery, bad alternator, or jump-starting incorrectly) that corrupted memory during a write operation
- A failed or interrupted software update/reflash
- Genuine internal ECU hardware failure — less common, but possible on an older module
How to diagnose it
- Check battery and charging system health first, since electrical instability is the most common trigger
- Clear the code and see if it returns — a one-time voltage glitch may not recur
- If it returns consistently, the ECU likely needs reprogramming or replacement, which is a job for a workshop with the right software
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Code names are compiled from open/standardized SAE and ISO references. Explanations, symptoms, causes and fixes are original. Covers generic (P0/C0/B0/U0) codes only — manufacturer-specific codes are planned for a future update.
Frequently asked questions
Can I drive with P0601?
You can usually keep driving with P0601, but don't put it off — the underlying cause can get worse or lead to further damage the longer it goes unaddressed. Get it diagnosed as soon as you reasonably can.
How much does it cost to fix P0601?
Typical repair costs for {code} range from roughly 100 to 1500 EUR, depending on the specific cause and your car — see the fixes listed above for a breakdown.
What causes P0601?
A voltage spike or drop (from a weak battery, bad alternator, or jump-starting incorrectly) that corrupted memory during a write operation A failed or interrupted software update/reflash Genuine internal ECU hardware failure — less common, but possible on an older module
Reviewed by Artyom SemenovAutomotive Editor · Fact-checked by Yauheni Kapliarchuk, Editor-in-Chief