U0199 Lost communication with door control module A

Lost communication with door function control module A

Severity not verified — if the car runs badly, have it inspected

A door module dropping off the network usually costs windows, locks or mirrors, but complaints show it stored with many other modules during power-loss events and with a brake-assist voltage code.

It gets more serious if:

  • Inspect soon: Inspect soon if U0199 comes with reduced power, shifting problems or other lost-communication or low-voltage codes.

Source: how we rate severity

U0199 in short

U0199 means other modules lost communication with door control module A, usually the driver or front door module. You may lose power windows, locks or mirrors. A damaged door harness, an added aftermarket splice, or a power or ground problem is a common reason. It is rarely urgent alone, but check it if other warnings appear.

The door control module handles window, lock and mirror functions and reports over the vehicle network. If its messages stop, other computers store U0199.

A reference site defines U0199 as no communication with door function control module A. A 2013 Ford Fusion owner read it as lost communication with door control module A, stored with U0200 (door module B) and U0256 (front controls interface module), with windows and climate controls dead. A 2020 Honda Accord Hybrid owner reports a dealer tying U0199 (driver's door module), B1142 and U3003-16 to a non-genuine quick-splice connector in the driver's door harness.

A 2020 Ford F-150 owner lists U0199 inside a long string of lost-communication codes during a wrench warning, which suggests a shared network or power fault rather than a door problem.

Most likely causes

  1. Damaged or tampered door harness or connector

    Supported by vehicle data
    Why it ranks here
    A Honda owner reports a dealer found an aftermarket quick-splice in the driver's door harness linked to U0199; the Ford owner's intermittent loss at high heat also fits a wiring or connection fault. Both are owner accounts.
    What would change this
    Rises if the door harness has splices, chafing or a loose connector. Falls if other modules are offline too.

  2. Shared power, ground or network fault taking many modules offline

    Supported by vehicle data
    Why it ranks here
    A 2020 F-150 owner shows U0199 among thirteen lost-communication codes at once; one report.
    What would change this
    Rises if many modules drop together. Falls if only the door modules are affected.

  3. Door control module fault

    Possible — needs testing
    Why it ranks here
    The code names the module, but a lost-communication code does not say whether the module, its wiring or its power failed.
    What would change this
    Rises if the door functions are dead and power and ground at the module are good. Falls if other modules are offline.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all modules and note whether U0199 is stored alone, with the other door module code (U0200), or with many lost-communication codes.

    Low riskTool: Scan tool that reads all modules

  2. Check that the battery tests healthy, look for aftermarket splices or added wiring, and have a shop inspect the door jamb harness and connector for chafing, corrosion or loose terminals.

    Best left to a shopTool: Battery tester, visual inspection

    Warning:Door harnesses often run next to side airbags and the door lock circuits; do not unplug connectors or cut into the harness without following the service procedure and disconnecting the battery as specified.

Symptoms

  • Power windows, locks or mirrors not responding
  • Climate controls dead at the same time
  • Many warnings or reduced power with the code Gets more serious: stop and have it checked.

How to fix

  1. Check that the battery terminals are clean and tight and the battery tests healthy.

  2. Tell the shop about any aftermarket alarm, tracker or audio wiring.

On your vehicle

Ford

  • 2013 · Fusion

    Supported by vehicle data

    A 2013 Fusion owner read U0199 as lost communication with door control module A, stored with U0200 and U0256, with windows and climate controls inoperative.

Honda

  • 2020 · Accord

    Supported by vehicle data

    A 2020 Accord Hybrid owner reports a dealer linked U0199 (driver's door module) to a non-genuine quick-splice in the driver's door harness.

No curated relationships for U0199 yet.

All Module network (CAN bus) communication codes

U0199 questions

Is U0199 just a window problem?

Often the symptoms are windows, locks or mirrors, but it can also be one of many codes from a shared power or wiring fault, so read every code.

Sources and review

  1. U0199 generic definition — troublecodes.net
  2. NHTSA complaint ODI 11114676: 2013 Ford Fusion — NHTSA (owner complaint)
  3. NHTSA complaint ODI 11685172: 2020 Honda Accord Hybrid — NHTSA (owner complaint)
  4. NHTSA complaint ODI 11758824: 2020 Ford F-150 — NHTSA (owner complaint)
Last reviewed
Written by
Saurabh K.
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