Test D: The Trailer Brake Control (TBC) Module Does Not Respond to the Scan Tool

PINPOINT TEST D: THE TRAILER BRAKE CONTROL (TBC) MODULE DOES NOT RESPOND TO THE SCAN TOOL

D1-D2:

D2-D3:

D4:

Normal Operation
The TBC module communicates with the scan tool through the high speed controller area network (HS-CAN). Circuits 1908 (WH) (HS-CAN +) and 1909 (BK) (HS-CAN -) provide the network connection to the TBC module. The TBC module shares the HS-CAN network with the powertrain control module (PCM), the anti-lock brake system (ABS) module and the instrument cluster. Voltage for the TBC module is provided by circuits 50 (RD), 298 (VT/OG) and 1792 (PK). Ground is provided by circuit 206 (WH).

Possible Causes
- Fuse
- Circuit 50 (RD) open
- Circuit 206 (WH) open
- Circuit 298 (VT/OG) open
- Circuit 1792 (PK) open
- Circuit 1908 (WH) open
- Circuit 1909 (BK) open
- TBC module
- Vehicle is not equipped with optional module