brake control module.
9. Ignition ON, test for less than 1 V between the control circuit terminal D and ground.
锟斤拷If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the fuel pump/trailer
brake control module.
10. If all circuits test normal, replace the trailer brake solid state relay.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Trailer Brake Control Relay Replacement (1500) (See: Accessories and Optional Equipment/Towing / Trailer System/Trailer Towing
Relay/Service and Repair/Trailer Brake Control Relay Replacement (1500))Trailer Brake Control Relay Replacement (2500) (See:
Accessories and Optional Equipment/Towing / Trailer System/Trailer Towing Relay/Service and Repair/Trailer Brake Control Relay
Replacement (2500))
* Control Module References (See: Testing and Inspection/Programming and Relearning) for fuel pump/trailer brake control module
replacement, setup, and programming
Gasoline With LY6, or Diesel
DTC C0870, C1112, C1113, C1114, or C1119 (Gasoline With LY6, or Diesel)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC C0870 00
- Device Voltage Reference Output 1 Circuit
DTC C1112 00
- Trailer Brake Control Relay Low Control Circuit
DTC C1113 01
- Trailer Brake Control Relay High Control Circuit Short to Battery
DTC C1114 00
- Trailer Brake Control Solenoids Control Circuit
DTC C1119 00
- Trailer Brake Control Relay Feedback Circuit
Diagnostic Fault Information
Circuit/System Description
The trailer brake control relay receives inputs from the trailer brake control module (TBCM), these inputs are used to determine the amount of
voltage the relay will supply to the trailer brakes.
