The radio supplies voltage to the audio steering wheel control switches and monitors the return signal. Each switch state is associated to a set resistance value and when pressed a specific voltage drop occurs across the resistor unique to the switch. The radio identifies the switch selection and activates the feature.

Before diagnosis of the steering wheel controls, ensure the primary controls of the associated component are functioning properly.

Schematic Reference

Connector End View Reference

Component Connector End Views

Description and Operation

Steering Wheel Controls Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

1. Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
2. Ignition ON, radio ON, test for 9.8-10.2 volts between the voltage reference circuit terminal 2 and ground.

⇒	If greater than the specified range, test the voltage reference circuit for a short to voltage. If the circuit tests normal, replace the radio.

⇒	If less than the specified range, test the voltage reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.

3. Test for greater than 9 volts between the voltage reference circuit terminal 2 and the signal circuit terminal 4.

⇒	If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the radio.

4. Ignition OFF, disconnect the X1 harness connector at the radio.
5. Test for infinite resistance between the signal circuit terminal 4 and ground.

⇒	If less than the specified value, test the signal circuit for a short to ground.

6. If all circuits test normal, test or replace the right steering wheel control switch.

1. Disconnect the harness connector at the right steering wheel control switch.
2. Connect a DMM between terminals 2 and 4 of the right steering wheel control switch.

⇒	If any of the resistance measurements for the individual switches are not within the specified resistance values, replace the right steering wheel control switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.