2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 720
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
Control Module References (See: Testing and Inspection/Programming and Relearning) for trailer brake control module replacement,
programming and setup
DTC B3887 or B3888 (With U4G)
* 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 B3887 02
- Trailer Left Turn Signal Circuit Short to Ground
DTC B3887 04
- Trailer Left Turn Signal Circuit Open
DTC B3888 02
- Trailer Right Turn Signal Circuit Short to Ground
DTC B3888 04
- Trailer Right Turn Signal Circuit Open
Diagnostic Fault Information
The trailer brake control module will receive a serial data message from the BCM indicating that the vehicle left turn signal lamp or the right turn
signal lamp has been activated. The trailer brake control module will then apply a pulsating voltage to the appropriate trailer turn signal lamps
through their respective voltage supply circuits.
Conditions for Running the DTC
When the trailer left turn lamp or right turn lamp is being actively commanded by the trailer brake control module.
Conditions for Setting the DTC
B3887 02 or B3888 02
The trailer brake control module detects a short to ground on the appropriate turn signal control circuit.
B3887 04 or B3888 04
The trailer brake control module detects an open/ high resistance in the appropriate turn signal control circuit.
Action Taken When the DTC Sets
The appropriate trailer turn signal lamp will be inoperative.
Conditions for Clearing the DTC