Lost Communication With Door Control Module E
What it means
U0203 means the vehicle has lost communication with door control module "E" — the small module that runs one door's power window, lock, mirror, and switches. When it goes offline, that door's powered features stop working, but nothing about how the car drives is affected. The most common cause is a broken or chafed wire in the door-jamb harness, which flexes every time the door opens; connector, power/ground, or bus faults are also possible.
Can I keep driving? Yes — the car drives normally. You'll just lose power features (window, lock, or mirror) for the affected door until it's repaired.
Common symptoms
What you'll notice
- Power window, lock, or mirror on one door stops working
- Door switches on that door are unresponsive
- Warning message or lights for door/body electronics
- Scan tool can't reach door control module E
Common causes
Most likely first
- Wiring or connector fault at the door module (the jamb harness flexes every time the door opens)Likely
- Power or ground problem to the moduleCommon
- Failed door control moduleCommon
- CAN bus wiring fault to the moduleLess often
How to diagnose & fix
Work through it in order
- Confirm the code and note which door features are lost.
- Inspect the door-jamb harness and connector for broken or chafed wires.
- Check the module's power and ground.
- Verify bus communication to the module.
- Replace and program the door control module if it's confirmed faulty.
FAQ
Quick answers
Is it safe to drive with U0203?+
Can I just clear U0203?+
Related codes
Often seen with U0203
Read & clear U0203 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.