OnStar One or More Buttons Inoperative

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Cadillac Escalade EXT. However, it is still accessible from the selected car via links, so may be relevant.

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