What Does U0199 Mean?
Communication has been lost between the control module detecting the fault and Door Control Module A (typically driver door module). This prevents proper operation of door-related functions on that specific door.
Common Causes
30%
Door control module power or ground circuit failure
28%
CAN bus wiring fault in door harness (open, short, or damaged by door flexing)
25%
Door control module internal failure
12%
Connector corrosion or damage in door jamb area
5%
Network circuit short to ground or power
Diagnostic Steps
1
Step 1: Inspect door harness in door jamb area for pinching, wear, or damage from repeated door opening/closing
2
Step 2: Check power and ground at door control module connector with multimeter (key on)
3
Step 3: Measure CAN bus voltage at door module connector - should see approximately 2.5V on each CAN line with fluctuation during communication
4
Step 4: Disconnect door module and check for short circuits in harness; verify other modules still communicate properly
5
Step 5: Replace door control module if wiring and power are verified good, then reconfigure/program as required
Estimated Repair Cost
$200 - $800
Parts + labor, varies by vehicle and location
Communication has been lost between the control module detecting the fault and Door Control Module A (typically driver door module). This prevents proper operation of door-related functions on that specific door.
The most common cause of U0199 (Lost Communication With "Door Control Module A") is: Door control module power or ground circuit failure
Typical repair costs for U0199 range from $200 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Generally safe to drive. Door locks, windows, mirrors, and courtesy lighting on affected door may not function properly.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U0199 to identify the root cause.
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Quick Info
Category
Network
System
Body Control/Door Systems
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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