B2482

DTC B2482

CIRCUIT DESCRIPTION
The OnStar(R) button assembly consists of 3 buttons, Call/Answer, OnStar(R) Call Center and OnStar(R) Emergency. Ten volts is supplied to the button assembly on the keypad supply voltage circuit. Each of the buttons, when pressed, completes the circuit across a resister allowing a specific voltage to be returned to the vehicle communication interface module (VCIM) on the keypad signal circuit. Depending upon the voltage range returned, the VCIM is able to identify which button has been pressed.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC B2482 Cellular Phone Select Service Switch Range/Performance




This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description in Vehicle DTC Information. DTC Symptom Description

CONDITIONS FOR RUNNING THE DTC
- The ignition must be in the RUN or ACC position.
- The system voltage is at least 9.5 volts and no more than 15.5 volts.
- All the above conditions are present for greater than 15 seconds.

CONDITIONS FOR SETTING THE DTC
- A button is pressed or stuck for more than 15 seconds.
- The above conditions are present for greater than 15 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The VCIM will ignore all inputs from the OnStar(R) button assembly.
- No calls can be placed.
- The OnStar(R) status LED turns red.

CONDITIONS FOR CLEARING THE DTC
- The button will be declared unstuck after a 50 millisecond normal cycle.
- A history DTC clears after 50 malfunction free ignition cycles.
- The VCIM receives the clear DTC command from the scan tool.

TEST DESCRIPTION

Step 1 - Step 9:

The number below refers to the step number on the diagnostic table.
2. This step tests the at rest state of the keypad signal circuit.