Lost Communication With Trailer Chassis Control Module
The U0204 code means the vehicle's onboard diagnostic system has detected: Lost Communication With Trailer Chassis Control Module. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $250 - $700 (parts and labor)
Network codes mean modules are not communicating. You need a scanner that reads all systems to find the problem.
Check Price on AmazonAffiliate link -- we earn a commission at no extra cost to you.
Common Symptoms
- Trailer stability control warning
- Trailer sway detection not working
- ABS warning light for trailer
- Reduced towing capability message
Probable Causes (Ranked by Likelihood)
- Failed trailer chassis module Very High
- Damaged communication wiring to trailer High
- Incompatible trailer control system Moderate
- Poor ground connection at trailer plug Low
Step-by-Step Diagnostic Procedure
-
Check trailer 7-pin connector wiring
-
Verify ground pin continuity at trailer plug
-
Scan trailer module for stored codes
-
Test CAN communication between truck and trailer
Frequently Asked Questions
Is it safe to tow with U0204?
Drive only short distances at reduced speed. Trailer stability control is compromised.
What causes U0204?
Typically a damaged trailer wiring harness or failed trailer chassis control module.
How much does U0204 cost to fix?
Between $250 and $700 depending on wiring repair versus module replacement.
Sources
This page is built from documented references. Verify against your own service info before repair work.
Explore More
Was this helpful?
Share carcodefinder.com with a friend who needs to decode their check engine light.