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

The body control module (BCM) supplies voltage 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.

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 BCM data list . Pressing the switch should read voltage present, and drop to 0 volts when released.

NOTE: 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 harness connector at the left and right audio steering wheel control switches.
2. Ignition ON, test for 10-12 volts between the supply voltage circuit and ground at the right switch harness connector.

⇒	If less than 10 volts, test the supply voltage circuit for short to ground or open/high resistance. If circuit test normal, replace BCM.

3. Install a 3-amp fused jumper wire at the right switch supply voltage circuit. Toggle the jumper wire to the signal circuits at the left and the right harness connectors. Verify DTC B2815 sets.

⇒	If DTC B2815 does not set, test the signal circuits for a short to ground or open/high resistance. If circuit test normal, replace BCM.

4. Remove the 3-amp fused jumper wire.
5. Reconnect the right switch.
6. Ignition ON, test for 10-12 volts between the supply voltage circuit and ground at the left switch harness connector.

⇒	If less than 10 volts, test the supply voltage circuit for short to ground or open/high resistance. If circuit test normal, refer to component testing.

7. 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 suspect audio steering wheel control switch.
2. Test the right switch for 2360-2400 ohms of resistance between the supply voltage terminal and the supply voltage terminal for the left switch.

⇒	If the resistance is not between 2360-2400 ohms, replace faulty switch.

3. Test the switch for infinite resistance between the supply voltage terminal and the signal terminal with the switch in the open position.

⇒	If less than infinite resistance, replace the switch.

4. Test resistance values between the supply voltage 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.