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Home >> Cadillac >> 2009 >> Escalade EXT >> Repair and Diagnosis >> External Pages >> Different car >> Section 8 (Cellular System, Entertainment System, And Navigation System) >> Diagnostic Information and Procedures >> No (or Noisy) OnStar Audio >> Test Description
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Test Description

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The number below refers to the step number on the diagnostic table.

  1. 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: Entertainment/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 Diagnostic System Check - Vehicle? Go to Step 2  Go to Diagnostic System Check - Vehicle
2
  1. Turn ON the ignition, with the engine OFF.
  2. Turn ON the radio.
  3. Set volume to a comfortable level.
  4. Press the OnStar® Center Call button.
Can the Connecting to OnStar message be heard playing through the audio system at all?
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 
4 Test the cellular telephone voice low reference circuit for an open. Refer to Circuit Testing and Wiring Repairs .
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 .
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 a short to voltage. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?
Go to Step 11  Go to Step 8 
Test the cellular telephone voice low reference circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs .
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 .
Did you find and correct the condition?
Go to Step 11  Go to Step 10 
10 Replace the VCIM. Refer to Control Module References for replacement, setup, and programming.
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