Symptom Chart: Trailer Brake System
WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
Diagnostics in this article assume a certain skill level and knowledge of Ford-specific diagnostic practices. REFER to: Diagnostic Methods .
Symptom Chart
| Condition | Actions |
|---|---|
| The trailer brakes are inoperative | GO to Pinpoint Test A |
| The trailer brakes are always engaged | GO to Pinpoint Test B |
| The message center displays TRAILER BRAKE MODULE FAULT | GO to Pinpoint Test C |
| The message center displays TRAILER WIRING FAULT | GO to Pinpoint Test C |
| The message center intermittently displays TRAILER DISCONNECTED or TRAILER WIRING FAULT while towing a trailer | GO to Pinpoint Test C |
| The message center displays TRAILER BRAKE MODULE FAULT when the vehicle is not equipped with a TBM | GO to Pinpoint Test G |
| The message center displays TRAILER DISCONNECTED, TRAILER GAIN XX.XX, NO TRAILER after a trailer is connected to the vehicle and the manual slider switch is moved or a gain button is pressed. | GO to Pinpoint Test F |
| The message center intermittently displays TRAILER DISCONNECTED or WIRING FAULT ON TRAILER while towing a trailer | GO to Pinpoint Test C |
| The message center displays WIRING FAULT ON TRAILER | GO to Pinpoint Test C |
| The message center displays TRAILER CONNECTED message when no trailer is connected to the vehicle | GO to Pinpoint Test D |
| The message center displays a false TRAILER DISCONNECTED message when a trailer is connected to the vehicle | GO to Pinpoint Test E |
| After market trailer connection C2142 inoperative | GO to Pinpoint Test L |