2010 Cadillac Truck SRX AWD V6-3.0L Page 459
B1405 07, B1529 07, or B257B 07
The BCM detects a voltage greater than 12.2 V on dimmer switch signal circuit.
Action Taken When the DTC Sets
The BCM will not dim or illuminate any LED backlighting supplied by the backlight lamp control circuits.
Conditions for Clearing the DTC
* The condition responsible for setting the DTC no longer exists.
* A history DTC will clear once 100 consecutive fault free ignition cycles have occurred.
Reference Information
Schematic Reference
* Interior Lights Dimming Schematics (See: Diagrams/Electrical Diagrams/Lighting and Horns/System Diagram/Interior Lights Dimming
Schematics)
* Steering Wheel Secondary/Configurable Control Schematics (See: Accessories and Optional Equipment/Diagrams/Electrical
Diagrams/Steering Wheel Secondary/Configurable Control Schematics)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views/Connector End Views By Name)
Description and Operation
Interior Lighting Systems Description and Operation (See: Lighting and Horns/Description and Operation/Interior 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, headlamps ON, vary the interior backlight dimming from low to full bright by using the dimmer switch. The interior backlighting
should start dim and then become full bright.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the S30 headlamp switch.
2. Test for less that 10 Ohms between the ground circuit terminal 6 and ground.
瀚慖f greater than the specified range, test the ground circuit for an open high/resistance.
3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 1 and ground.
瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace
the K9 BCM.
4. Ignition ON, test for less than 0.3 V between signal circuit terminal 12 and ground.
瀚慖f greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.
5. Install a 3 A fused jumper wire between the signal circuit terminal 12 and the B+ circuit terminal 1. The interior backlighting should be
dimmed.
瀚慖f the interior backlighting is not dimmed, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests
normal, replace the K9 BCM.
