Some owners of a 2007-08 Silverado or Sierra with RPO JL1 may comment of a Service Trailer Brake System message displayed on the DIC. DTCs C1112 and/or C1114 will be set in the Trailer Brake Control Module (TBCM).
TIP: This concern may occur with or without a trailer connected to the vehicle.
Updated TBCM calibrations have been released in TIS2Web to improve TBCM diagnostics for a high resistance short to voltage concern. The Tech 2 can be used to monitor the TBCM Relay Feedback Signal parameter located under Chassis/Trailer Brake Control Module/Data Display to help determine if there is a short to voltage.
The normal voltage reading is between 3.2-4.1 volts. If the voltage is higher, the updated calibration will help. If the voltage is lower, the updated calibration should still be installed. However, additional diagnostics may be needed to correct the concern.
TIP: Refer to the latest version of PIT4595D and appropriate SI diagnostics for additional help.
- Thanks to Jim Will
TIP: This concern may occur with or without a trailer connected to the vehicle.
Updated TBCM calibrations have been released in TIS2Web to improve TBCM diagnostics for a high resistance short to voltage concern. The Tech 2 can be used to monitor the TBCM Relay Feedback Signal parameter located under Chassis/Trailer Brake Control Module/Data Display to help determine if there is a short to voltage.
The normal voltage reading is between 3.2-4.1 volts. If the voltage is higher, the updated calibration will help. If the voltage is lower, the updated calibration should still be installed. However, additional diagnostics may be needed to correct the concern.
TIP: Refer to the latest version of PIT4595D and appropriate SI diagnostics for additional help.
- Thanks to Jim Will
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