P0601
Internal Control Module Memory Checksum Error
Engine control module (ECM)
Generic OBD-II
High
What it means
P0601 means the engine control module ran an internal check on its own memory and the result didn't match — a checksum error. The ECM can't fully trust its stored data, so the engine may not start, may stall, or drop into limp mode. Check battery voltage and grounds first, since those can trigger it without a failed module.
High
Can I keep driving? Not really — the ECM can't trust its own memory, so the engine may not start, may stall, or run in limp mode; treat it as a get-it-fixed-now fault.
Common symptoms
What you'll notice
- Check-engine light on, often with other warning lights
- No-start or intermittent stalling
- Reduced power / limp mode
- Erratic behavior across multiple systems
Common causes
Most likely first
- Corroded, loose, or damaged ECM power and ground connectionsLikely
- Low battery voltage or a weak charging system disrupting the moduleCommon
- An interrupted or incorrectly installed software/reflash updateCommon
- Internal ECM memory failureLess often
How to diagnose & fix
Work through it in order
- Check the battery and charging system first — low or unstable voltage is a common trigger; clean and tighten battery and ground connections.
- Inspect the ECM connectors and grounds for corrosion, damage, or looseness and repair as needed.
- If the module was recently reflashed, have a technician re-flash it correctly with the latest calibration.
- If voltage, grounds, and software are good and the checksum error persists, the ECM needs replacement and programming.
FAQ
Quick answers
Is it safe to drive with P0601?+
No. When the module can't verify its own memory it may cut fueling, stall, or refuse to start. Have it diagnosed before relying on the vehicle.
Can I just clear P0601?+
Clearing rarely holds — an internal memory error returns immediately. Rule out battery voltage and grounds first, as those can trigger it without a bad ECM.
Related codes
Often seen with P0601
Read & clear P0601 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX