OnStar One or More Buttons Inoperative

Step	Action	Value(s)	Yes	No
Schematic Reference: OnStar Schematics DEFINITION: One or all buttons on the OnStar® button assembly are inoperative.
1	Did you perform the Cellular Communication Diagnostic System Check?	-	Go to Step 2	Go to Diagnostic System Check - Cellular Communication
2	IMPORTANT: Contact the OnStar® call center first before pressing the emergency button in order to notify them of the impending test. Turn ON the ignition, with the engine OFF. Press each OnStar® button one at a time. Are all buttons inoperative?	-	Go to Step 4	Go to Step 3
3	Are any buttons intermittent or inoperative?	-	Go to Step 7	Go to TESTING FOR INTERMITTENT AND POOR CONNECTIONS
4	Turn OFF the ignition. Disconnect the OnStar® button assembly. Turn ON the ignition, with the engine OFF. Measure the voltage from the keypad supply voltage circuit to a good ground. Does the voltage measure greater than the specified value?	9 V	Go to Step 6	Go to Step 5
5	Test the keypad supply voltage circuit for an open or short. Refer to CIRCUIT TESTING and WIRING REPAIRS . Did you find and correct the conditon?	-	Go to Step 11	Go to Step 8
6	Test the keypad signal circuit for an open or short. Refer to CIRCUIT TESTING and WIRING REPAIRS . Did you find and correct the condition?	-	Go to Step 11	Go to Step 9
7	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 11	Go to Step 9
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 11	Go to Step 10
9	Replace the OnStar® button assembly. Refer to OnStar Button Assembly Replacement (Utility) . Did you complete the replacement?	-	Go to Step 11	-
10	IMPORTANT: Perform the OnStar® setup procedure. Replace the VIU. Refer to OnStar Vehicle Interface Unit (VIU) Replacement .Did you complete the replacement?	-	Go to Step 11	-
11	Operate the system in order to verify the repair. Did you correct the condition?	-	System OK	Go to Step 2