U0199: Lost Communication with Door Control Module

What it means

A control module is not receiving expected messages from the Door Control Module. Functions controlled by that module may be affected; the code alone does not identify why communication was lost.

How it works

The Door Control Module operates or reports functions for a vehicle door and communicates with other modules over the network. U0199 sets when the reporting module stops receiving the door module's expected messages for the specified timeout.

Common causes

Most likely first.

1. Door module unpowered (often broken wires in door hinge)
2. Water ingress into door module
3. Gateway module routing CAN messages incorrectly

Symptoms

• Door-related functions may be unavailable or impaired
• Other communication codes

How to diagnose it

1. Scan all modules and note which door module is offline, along with freeze-frame data and other communication codes, to narrow the affected network branch.
2. Check battery condition and system voltage, then verify power and ground at the named door control module.
3. Inspect the wiring in that door's hinge area for broken conductors and check the module connector for corrosion or water intrusion.
4. Check the door module's network wiring for an open or short using the vehicle wiring diagram.
5. If power, ground, and wiring are sound, test network communication at the door module and check gateway status against the manufacturer's service information.

Common fixes

• Repair broken wiring in the affected door hinge harness.
• Clean or repair a corroded connector and address any water ingress at the door module.
• Restore the door module's power or ground supply.
• Repair a confirmed CAN wiring or gateway routing fault affecting that door.
• Replace or reprogram the door control module if it remains offline after circuit checks.

Can I keep driving?

The affected door's powered functions may be impaired, so check that its locks, windows, and latch operate correctly before driving. If the door will not latch securely, do not drive until it is repaired; other cases may leave driving unaffected but can reduce security or convenience.