Lost Communication With Door Control Module A
What it means
U0199 sets when the network loses contact with door control module A, which runs that door's power windows, locks, and mirror. Those convenience functions on the affected door may stop working and a warning light can appear; the vehicle otherwise drives normally.
Can I keep driving? Yes — the car drives fine; you may lose power windows, locks, or mirror on the affected door until it's repaired.
Real-world scan data
Appears alongside · share of U0199 scans
Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.
Common symptoms
What you'll notice
- Power window, lock, or mirror on one door not working
- Door control module missing from a scan
- Warning or indicator light
- Sometimes companion communication codes
Common causes
Most likely first
- Damaged or corroded wiring in the door harness (flexes at the hinge)Likely
- Blown fuse or lost power/ground to the door moduleCommon
- CAN bus fault to the moduleCommon
- Failed door control moduleLess often
- Water intrusion into the door connectorLess often
How to diagnose & fix
Work through it in order
- Scan for other communication codes to gauge the scope.
- Inspect the door-jamb harness where it flexes — a common break point.
- Check the module's fuse, power, and ground.
- Verify bus wiring continuity into the door.
- If supply and bus are good, suspect the door control module.
FAQ
Quick answers
Is it safe to drive with U0199?+
Can I just clear U0199?+
Related codes
Read & clear U0199 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.