Lost Communication With Trailer Brake Control Module
The U0202 code means the vehicle's onboard diagnostic system has detected: Lost Communication With Trailer Brake Control Module. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $200 - $600 (parts and labor)
Network codes mean modules are not communicating. You need a scanner that reads all systems to find the problem.
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Common Symptoms
- Trailer brake warning light illuminated
- Trailer brakes not functioning
- Reduced trailer braking force
- Brake controller display blank or error
Probable Causes (Ranked by Likelihood)
- Failed trailer brake control module Very High
- Damaged trailer wiring harness High
- Corroded trailer connector pins Moderate
- Faulty trailer brake controller ground Moderate
Step-by-Step Diagnostic Procedure
-
Inspect 7-pin trailer connector for corrosion
-
Check trailer brake controller power and ground
-
Test CAN bus communication at trailer module
-
Verify trailer brake wiring continuity
Frequently Asked Questions
Is it safe to tow with U0202?
No. Without trailer brakes, stopping distance increases dramatically. Do not tow until resolved.
What causes U0202?
Most commonly corrosion at the 7-pin trailer connector or damaged wiring in the trailer harness.
How do I fix U0202?
Start by cleaning the trailer connector pins. If that does not help, check the wiring and module.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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