Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

The body control module (BCM) supplies 12 volts to the audio steering wheel control multiple momentary contact switches and monitors the return signal. Each switch is associated to a set resistance value, when pressed a specific voltage drop occurs through a series of resistors unique to that switch. The BCM identifies the selection, then sends a serial data message that is received by the component controlled, activating the feature.

The ignition is ON.

The BCM detects a switch voltage that is higher than normal.

The BCM will ignore the switch command.

Schematic Reference

Steering Wheel Schematics

Connector End View Reference

Electrical Information Reference

Ignition ON, observe the scan tool steering wheel controls (SWC) Switch Voltage parameter in the body control module (BCM) data list . Pressing the switch should read voltage present, and drop to 0 volts when released.

It is recommended that Component Testing is performed before Circuit Testing when diagnosing steering wheel controls.

Caution: Refer to SIR Caution in the Preface section.

1. Ignition OFF, disconnect the right steering wheel control connector.
2. Ignition ON, with a scan tool, verify the SWC Switch Voltage parameter is at 0 volts.

⇒	If over 0 volts, test the remote radio control signal circuit for a short to voltage. If the circuits test normal, replace the BCM.

3. If all circuits test normal, refer to Component Testing.

Caution: Refer to SIR Caution in the Preface section.

1. Ignition OFF, disconnect the harness connector at the audio steering wheel control switches.
2. Test the switch for infinite resistance between the voltage supply terminal and the signal terminal with the switch in the open position.

⇒	If less than infinite resistance, replace the switch.

3. Test resistance values between the voltage supply terminal and the signal terminal with the switch closed in each position and verify readings are approximate to what the schematic reads.

⇒	If values do not, replace the switch.

Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.