锟斤拷If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace
the trailer brake control module.
锟斤拷If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the trailer brake control
module.
10. If all circuits test normal, test or replace the trailer brake controller switch panel.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Trailer Brake Control Switch Replacement (See: Accessories and Optional Equipment/Towing / Trailer System/Trailer Brake Control
Module/Service and Repair/Trailer Brake Control Switch Replacement)
* Trailer Brake Control Module Replacement (See: Accessories and Optional Equipment/Towing / Trailer System/Trailer Brake Control
Module/Service and Repair/Trailer Brake Control Module Replacement)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for TBCM replacement, setup, and programming
Gasoline Without LY6
DTC C0870, C1112, C1113, C1114, or C1119 (Gasoline Without LY6)
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 fuel pump/trailer brake control module, these inputs are used to determine the amount of
voltage the relay will supply to the trailer brakes.
Conditions for Running the DTC
