B2482

DTC B2482

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B2482 00
- Cellular Phone Select Service Switch Range/Performance

Circuit/System 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.

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.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the inside rearview mirror.
2. Ignition ON, test for less than 1 volt at the keypad signal terminal 11.

• If greater than specified value, test the circuit for short to voltage. If the circuit tests normal, test or replace the VCIM.

3. Test for less than 1 ohm of resistance between the VCIM and inside rearview mirror.

• If greater than specified value, test the circuit for open/high resistance, or for short to ground.

4. If the circuit tests normal, test or replace the inside rearview mirror.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Rearview Mirror Replacement for rearview mirror replacement
* Programming and Relearning Programming and Relearning