Normal Operation
WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
The Trailer Brake Control (TBC) module receives battery voltage from Battery Junction Box (BJB) fuse 22 (30A) and ignition voltage from Body Control Module (BCM) fuse 35 (5A).
- DTC B1863 (Ground ECU Circuit Open) - Sets when the TBC module detects an open circuit in the wiring, a connector condition causes an open in the ground circuit or if an internal failure of the TBC module causes an open in the ground circuit. The TBC module also disables trailer braking and sends a TRAILER BRAKE MODULE FAULT message to the message center. A trailer must be connected for this DTC to set.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- TBC module