Symptom Chart: Trailer Lamps
Diagnostics in this article assume a certain skill level and knowledge of Ford-specific diagnostic practices. REFER to SERVICE INFORMATION , Diagnostic Methods for information regarding Ford-specific diagnostic practices.
Symptom Chart: Trailer Lamps
| Condition | Possible Sources | Actions |
| A module does not respond to the scan tool | Fuse Wiring, terminals or connectors Module |
REFER to COMMUNICATIONS NETWORK , Symptom Chart: Communication Network. |
| All the trailer lamps are inoperative | Wiring, terminals or connectors Trailer tow connector Trailer |
GO to Pinpoint Test AH |
| The trailer stop-turn lamp is inoperative | Fuse Wiring, terminals or connectors Trailer tow stop/turn lamp relay Trailer tow connector Trailer |
GO to Pinpoint Test AI . |
| The trailer parking lamps are inoperative | Fuse Wiring, terminals or connectors Trailer tow parking lamp relay Trailer tow connector Trailer |
GO to Pinpoint Test AJ . |
| The trailer reversing lamps are inoperative | Fuse Wiring, terminals or connectors Trailer tow reversing lamp relay Trailer tow connector Trailer |
GO to Pinpoint Test AK |
| The trailer lamps are on continuously | Wiring, terminals or connectors Trailer tow relay Trailer |
GO to Pinpoint Test AL . |
| The trailer battery charging is inoperative or operates with the ignition off | Fuse Wiring, terminals or connectors Trailer tow battery charge relay Trailer tow connector Trailer |
GO to Pinpoint Test AM |
| The trailer electric brakes are inoperative or always applied | Fuse Wiring, terminals or connectors TBC module Trailer tow connector Trailer BCM |
GO to Pinpoint Test AN |