2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 727
3. If all the circuits test normal, replace the K9 BCM.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Fuse Block Replacement (See: Maintenance/Fuses and Circuit Breakers/Fuse Block/Service and Repair/Removal and Replacement/Fuse
Block Replacement)
* Control Module References (See: Testing and Inspection/Programming and Relearning)for BCM replacement, programming and setup
B3889
DTC B3889
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 B3889 02
- Trailer Brake Lamps Circuit Short to Ground
DTC B3889 04
- Trailer Brake Lamps Circuit Open
Diagnostic Fault Information
Circuit/System Description
The trailer brake control module will receive a serial data message from the BCM indicating that the vehicle brake lamps have been activated. The
trailer brake control module will then apply system voltage to the trailer stop lamps through their respective voltage supply circuits.
Conditions for Running the DTC
When the brake pedal is pressed.
Conditions for Setting the DTC
B3889 02
The trailer brake control module detects a short to ground on the trailer stop lamp control circuit.
B3889 04
The trailer brake control module detects an open/ high resistance on the trailer stop lamp control circuit.
Action Taken When the DTC Sets
The trailer brake lamps will be inoperative.
Conditions for Clearing the DTC
* The DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history DTC.
* A history DTC will clear after 40 ignition cycles.
