U0201
Lost Communication With Door Control Module C
Communication network (door module)
Generic OBD-II
Low
What it means
U0201 means the network has lost communication with door control module C, the unit that runs one door's power window, lock, and mirror. With it offline those features on that door stop working, often because the wiring in the flexing door-jamb harness has broken. The car drives normally and the fix is usually a harness or connector repair at that door.
Low
Can I keep driving? Yes — one door's power features may not work, but the car drives normally. Just make sure that door still locks manually.
Common symptoms
What you'll notice
- Power window, lock, or mirror on that door dead or intermittent
- Door control module C unreachable when scanned
- Possible warning message for that door's functions
- No effect on how the engine or brakes drive
Common causes
Most likely first
- Open, shorted, or chafed wiring in the door jamb harness (flexes every time the door opens)Likely
- Corroded or loose connector at the door moduleCommon
- Blown fuse or lost power/ground to the moduleCommon
- Failed door control moduleLess often
- Bus fault preventing the module from reportingLess often
How to diagnose & fix
Work through it in order
- Scan all modules and confirm door module C is offline.
- Inspect the door-jamb harness boot where wires flex for breaks or chafing.
- Check the module's power, ground, and fuse feeds.
- Test the connector and bus lines at the door module for open or short.
- If wiring and power are good, replace the door control module, clear the code, and confirm the door's features work.
FAQ
Quick answers
Is it safe to drive with U0201?+
Yes. Only that door's power features (window, lock, mirror) are affected. Confirm the door can still lock and latch, and the car is fine to drive.
Can I just clear U0201?+
It returns while the module stays offline. The wiring — usually in the flexing door-jamb harness — or the module itself needs repair.
Related codes
Often seen with U0201
Read & clear U0201 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