Test Description
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2005 Isuzu Ascender, 2005 GMC Envoy XUV, 2005 GMC Envoy XL, 2005 GMC Envoy, and 2005 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
The number below refers to the step number on the diagnostic table.
- 2: This step checks that the VCIM is sending out the proper supply voltage.
DTC B2455
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| Schematic Reference: OnStar® Schematics Connector End View Reference: Cellular Communication Connector End Views |
||||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
| 2 |
|
9 V | Go to Step 4 | Go to Step 3 |
| 3 | Test the cellular microphone 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 9 | Go to Step 6 |
| 4 | Test the cellular microphone low reference circuit for an open. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 9 | Go to Step 5 |
| 5 | Inspect for poor connections at the harness connector of the cellular microphone and harness connector of the vehicle communication interface module (VCIM). 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 9 | Go to Step 7 |
| 6 | Inspect for poor connections at the harness connector of the VCIM. 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 9 | Go to Step 8 |
| 7 | Replace the cellular microphone. Refer to OnStar® Microphone Replacement . Did you complete the replacement? |
- | Go to Step 9 | - |
| 8 | Replace the VCIM. Refer to Control Module References
in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? |
- | Go to Step 9 | - |
| 9 |
|
- | Go to Step 2 | System OK |