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Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 3:  This step determines if the OnStar® status LED has the necessary GREEN LED signal circuit voltage.
  2. 5:  If the GREEN LED signal is shorted to voltage, then the OnStar® 3-button assembly has been damaged and must be replaced.
OnStar Button LED Inoperative

Step Action Values Yes No
Schematic Reference: OnStar Schematics 
Connector End View Reference: Entertainment/Communication Connector End Views 
DEFINITION: This procedure is for diagnosing problems with the OnStar® button assembly LED.
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
2
  1. Turn the ignition ON, with engine OFF.
  2. Observe the OnStar® status LED.
Did the OnStar® status LED turn GREEN?
- Go to Testing for Intermittent Conditions and Poor Connections and Connector Repairs Go to Step 3 
Measure the voltage from the keypad GREEN LED signal circuit to a good ground.
Does the voltage measure near the specified value?
7 V Go to Step 6  Go to Step 4 
4 Test the keypad GREEN LED signal circuit for an open, high resistance, or a short to ground. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?
- Go to Step 10  Go to Step 5 
Test the keypad GREEN LED signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?
- Go to Step 7  Go to Step 8 
6 Inspect for poor connections at the harness connector of the rearview mirror. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?
- Go to Step 10  Go to Step 7 
7 Replace the rearview mirror. Refer to Rearview Mirror Replacement .
Did you complete the repair?
- Go to Step 10  -
8 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 10  Go to Step 9 
9 Replace the VCIM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the repair?
- Go to Step 10  -
10 Operate the system in order to verify the repair.
Did you correct the condition?
- System OK Go to Step 2