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.
- 2: This step test determines if the problem exists in the wiring or the BCM.
- 3: Inspects for poor connections before a component is replaced.
- 4: After replacement of the BCM you must calibrate the new module for proper operation.
DTC B2550 Diagnostic Test
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Exterior Lights 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 |
| 2 | Test the following circuits as indicated. 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 |
| 3 | 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 5 | Go to Step 4 |
| 4 |
IMPORTANT:
Perform the setup procedure for the BCM. Replace the body control module (BCM). Refer to Body Control Module Replacement
in Body Control System.Did you complete the replacement? |
Go to Step 5 | - |
| 5 |
|
Go to Step 2 | System OK |