P0601 means Internal Control Module Memory Check Sum Error. The engine computer has found that its stored programming does not pass its internal memory check. It is a generic OBD-II code, so the definition is the same on any make, but the most likely cause varies by engine; confirm with a scan tool and the service information for your vehicle before buying parts.
What P0601 means
Modern vehicles have many control modules that share information over a network, usually called the CAN bus. Codes starting with U mean a module has stopped hearing another one, and voltage and processor codes mean a module is not getting clean power or has an internal fault. Low battery voltage, poor grounds, blown fuses and damaged wiring cause many of these codes, so test the battery and charging system first.
P0601 symptoms
- Check engine light
- No-start, stalling or poor running on some vehicles
- Several unrelated codes
Common causes of P0601
- Corrupted programming, sometimes after an interrupted update
- Low voltage during programming
- Internal module failure
How to diagnose P0601
- Check battery and charging voltage first
- Check for available software updates
- Reprogram the module with a stable power supply connected; replace it only if reprogramming fails
Can you drive with P0601?
It depends on symptoms; if the engine stalls or will not start, do not rely on the vehicle.
P0601 tips
Memory check sum codes sometimes follow a module update that was interrupted by low battery voltage. Always connect a battery maintainer before reprogramming any module.
Will P0601 clear itself?
If the fault stops, the computer turns off the check engine light by itself after several drive cycles without seeing it again, and the code stays in memory as history for a while. Clearing P0601 with a scan tool after a repair is fine, but if the cause is still there the code returns, sometimes within one drive. Disconnecting the battery also clears codes on most vehicles, but it erases learned fuel trims and idle settings as well.
Related codes
| Code | Meaning |
|---|---|
| P0606 | Control Module Processor |
| P0562 | System Voltage Low |
| U0100 | Lost Communication With ECM/PCM A |
Guides that help
When it is more than a sensor
Voltage and network codes come from wiring, the battery, the charging system or a module, not from engine or transmission wear. If a lost-communication code has left the transmission in limp mode, rule out the module and wiring before deciding the unit has failed, and see our transmissions only if testing confirms internal damage.
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