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 number below refers to the step number on the diagnostic table.
- 8: If the Cellular Telephone Voice Low Reference circuit is shorted to voltage the vehicle communication interface module (VCIM) has been damaged and requires replacement.
No (or Noisy) OnStar Audio
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: OnStar Schematics Connector End View Reference: Cellular Communication Connector End Views DEFINITION: This procedure is for diagnosing problems during OnStar® audio following a button press from the OnStar® button assembly. |
|||
| 1 | Did you perform the Cellular Communication Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Cellular Communication |
| 2 |
|
Go to Step 3 | Go to Step 5 |
| 3 | Tune the radio to a known good station. Can the audio be heard through all speaker channels? |
Go to Step 4 | Go to Diagnostic Starting Point - Entertainment in Entertainment |
| 4 | Test the cellular telephone voice low reference circuit for an open. Refer toCircuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 11 | Go to Step 9 |
| 5 | Is any distortion heard? | Go to Step 7 | Go to Step 6 |
| 6 | Test the cellular telephone voice signal 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 11 | Go to Step 7 |
| 7 | Test the cellular telephone voice signal circuit for an open or short to voltage. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
Go to Step 11 | Go to Step 8 |
| 8 | Test the cellular telephone voice low reference 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 10 | Go to Step 9 |
| 9 | Inspect for poor connections at the 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 11 | Go to Step 10 |
| 10 |
IMPORTANT:
Perform the OnStar® setup procedure. Replace the VCIM. Refer to Communication Interface Module Replacement .Did you complete the repair? |
Go to Step 11 | - |
| 11 | Operate the system in order to verify the repair. Did you find and correct the condition? |
System OK | Go to Step 2 |