Steering Wheel Controls Block Diagram
| Callout | Component Name |
|---|---|
| DA | Serial Data |
| HW | Hard-Wired |
| S70R | S70R Steering Wheel Controls Switch - Right |
| K9 | K9 Body Control Module |
| A11 | A11 Radio |
The steering wheel control switches duplicate the function of the primary controls of the associated component, through a network of momentary contact switches and a series of resistors. The body control module (BCM) supplies voltage to the switches and monitors the return signal. When a switch is pressed, a specific voltage drops across the resistor unique to that switch. The BCM identifies the switch selected and sends a serial data message to the component controlled by the switch, activating the feature.
This section is intended to diagnose the circuits between the BCM and the steering wheel control switches. If the primary control for the device is inoperative, refer to the appropriate section for the component the steering wheel control switch is used for.