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Test Description

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The numbers below refer to the step numbers on the diagnostic table.

  1. 3:  Tests for an open in the TBC 5 battery positive voltage supply circuit within the body wiring harness extension harness.
  2. 4:  Tests for voltage at the LED dimming signal circuit.
  3. 5:  Tests for voltage at the LED dimming signal circuit when the headlamp switch is in the OFF position.
  4. 11:  After replacement of the BCM, you must calibrate the new module for proper operation.
DTC B0951 Diagnostic Test

Step Action Yes No
Schematic Reference:  Interior Lights Dimming Schematics  
Connector End View Reference:  Lighting Systems Connector End Views   or  Body Control System Connector End Views  in Body Control System
1 Did you perform the Lighting Systems Diagnostic System Check? Go to Step 2  Go to Diagnostic System Check - Lighting Systems 
2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Use the scan tool to control the backlight dimming.
  4. Activate the affected control switch.
Does the control switch indicator lamp respond to the scan tool output control?		 Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems Go to Step 3 
3  Test the TBC 5 battery positive supply voltage circuit of the body wiring harness extension harness for continuity. Refer to Circuit Testing in Wiring Systems.
Is continuity present?		 Go to Step 4  Go to Step 7 
4 
  1. Turn the headlamp switch to PARK.
  2. Adjust the instrument panel (I/P) dimmer switch to the full illumination position.
  3. Probe the LED dimming signal circuit with a test lamp connected to a good ground.
Does the test lamp illuminate?		 Go to Step 5  Go to Step 9 
5 
  1. Turn the headlamp switch to the OFF position.
  2. Ensure that there is sufficient light to the ambient light sensor to prevent automatic lamp control (ALC) activation.
  3. Probe the LED dimming signal circuit with a test lamp connected to a good ground.
Does the test lamp illuminate?		 Go to Step 6  Go to Step 8 
6 Test the LED dimming signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 12  Go to Step 8 
7 Inspect for poor connections at the body wiring harness extension harness connectors. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 12  Go to Step 10 
8 Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 12  Go to Step 11 
9 Repair the open, high resistance or short to ground in the LED dimming signal circuit. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?		 Go to Step 12  -
10 Replace the body wiring harness extension harness to the BCM. Refer to Body Wiring Harness Extension Replacement - BCM in Body Control System.
Did you complete the replacement?		 Go to Step 12  -
11 
IMPORTANT: Perform the setup procedure for the BCM.
Replace the BCM. Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement?		 Go to Step 12  -
12
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?		 Go to Step 2  System OK
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