2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 717
Circuit/System Description
The trailer brake control module will receive a serial data message from the body control module (BCM) indicating that the vehicle park lamps
have been activated. The trailer brake control module will then apply system voltage to the trailer tail lamps through their respective voltage supply
circuits.
Conditions for Running the DTC
When the parking lamps are turned on.
Conditions for Setting the DTC
B3885 02 or B3886 02
The trailer brake control module detects a short to ground on the appropriate tail lamp control circuit.
B3885 04 or B3886 04
The trailer brake control module detects an open/high resistance in the appropriate tail lamp control circuit.
Action Taken When the DTC Sets
The appropriate trailer tail lamp 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.
Reference Information
Schematic Reference
Trailer Connector/Provision Schematics (See: Diagrams/Electrical Diagrams/Starting and Charging/Power and Ground Distribution/System
Diagram/Trailer Connector/Provision Schematics)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views/Connector End Views By Name)
Description and Operation
Exterior Lighting Systems Description and Operation (See: Lighting and Horns/Description and Operation/Exterior Lighting Systems)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic
Procedures/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Verification
Ignition ON, observe the function of the left trailer tail lamp and the right trailer tail lamp while commanding the Left Trailer Tail Lamp and the
Right Trailer Tail Lamp ON and OFF with a scan tool. The left trailer tail lamp and the right trailer tail lamp should turn ON and OFF while
changing between the commanded states.
Circuit/System Testing
1. Ignition OFF, disconnect the X1 harness connector at the K68 trailer lighting control module.
