Test Description
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. 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.
- 3: This step test determines if the problem exists in the wiring or the BCM.
- 4: This step test determines if the problem exists in the wiring or the BCM.
- 5: After replacement of the BCM you must calibrate the new module for proper operation.
DTC B2550
| 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 | Inspect the TBC 2B fuse in the instrument panel fuse block. Is the fuse open? |
Go to Step 3 | Go to Step 4 |
| 3 | Test the following circuits 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 6 | Go to Step 5 |
| 4 | Test the backup lamp supply voltage circuit for the following conditions:
Did you find and correct the condition? |
Go to Step 6 | Go to Step 5 |
| 5 |
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 6 | - |
| 6 |
|
Go to Step 2 | System OK |