Test Description

2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Test Description
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

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

  1. 2:  This step test determines if the problem exists in the wiring or the BCM.
  2. 3:  This step inspects for poor connections before a component is replaced.
  3. 4:  After replacement of the BCM you must calibrate the new module for proper operation.
DTC B2625 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 System Diagnostic System Check? Go to Step 2  Go to Diagnostic System Check - Lighting Systems 
Test the instrument panel lamps dimming control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 5  Go to Step 3 
Inspect for poor connections at the harness connectors of the body control module (BCM). 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 5  Go to Step 4 
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 5  -
5
  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
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.