Test D: The Auxiliary Audio Control Is Inoperative/Does Not Operate Correctly - Steering Wheel Controls

PINPOINT TEST D: THE AUXILIARY AUDIO CONTROL IS INOPERATIVE/DOES NOT OPERATE CORRECTLY - STEERING WHEEL CONTROLS

D1-D3:

D3-D5:

Normal Operation
The steering wheel controls consist of a specific resistor value for each button function creating a voltage divider. When a button is pressed, a specific reference voltage is sent to the audio unit. The audio unit then uses this reference voltage to determine which control input function has been selected. Circuit 595 (LB/RD) is the reference voltage circuit between the steering wheel controls and the audio unit.

Possible Causes
- Steering wheel controls
- Audio unit
- Clockspring
- Circuit 595 (LB/RD) open or short to ground
- Circuit 1205 (BK) open