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Home >> Cadillac >> 2002 >> Escalade EXT >> Repair and Diagnosis >> Accessories & Equipment >> Entertainment Systems >> Cellular Communication System >> Diagnostic Information and Procedures >> OnStar Button LED Inoperative >> Test Description

Test Description

This procedure is for diagnosing problems with the OnStar® button assembly. The following numbers refer to the steps in the table.

  1. 3:  Determines if the OnStar® status LED has the necessary GRN LED signal circuit.
  2. 5:  If the GRN LED signal is shorted to voltage then the OnStar® three button assembly has been damaged. The OnStar® three button assembly has to be replaced.
OnStar Button LED Inoperative

Step Action Value(s) Yes No
Schematic Reference: OnStar Schematics 
1 Did you perform the Cellular Communications Diagnostic System Check? - Go to Step 2  Go to Diagnostic System Check - Cellular Communication 
2
  1. Turn the ignition ON, with ignition OFF.
  2. Observe the OnStar® status LED.
Did the OnStar® status LED turn GREEN?		 - Go to TESTING FOR INTERMITTENT AND POOR CONNECTIONS and CONNECTOR REPAIRS Go to Step 3 
3 
  1. Turn the ignition OFF.
  2. Disconnect the OnStar® button assembly connector.
  3. Turn the ignition ON, with ignition OFF.
  4. Measure the Keypad GRN LED signal circuit voltage.
Does the voltage measure near the specified value?		 7-9 V Go to Step 6  Go to Step 4 
4 Test the keypad GRN 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 
5  Test the keypad GRN LED signal circuit for an 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 OnStar® button assembly. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS and CONNECTOR REPAIRS .
Did you find and correct the condition?		 - Go to Step 10  Go to Step 7 
7 Replace the OnStar® button assembly. Refer to OnStar Button Assembly Replacement (Utility) .
Did you complete the repair?		 - Go to Step 10  -
8 Inspect for poor connections at the harness connector of the VIU. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS and CONNECTOR REPAIRS .
Did you find and correct the condition?		 - Go to Step 10  Go to Step 9 
9
IMPORTANT: Perform the OnStar® setup procedure.
Replace the vehicle interface unit (VIU). Refer to OnStar Vehicle Interface Unit (VIU) Replacement .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 
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