The body control module (BCM) 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 BCM identifies the switch selection and activates the feature.

B1397

The BCM senses a short to ground in the voltage circuit for more than 1 second.

B2815

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

The BCM will ignore switch inputs.

Schematic Reference

Steering Wheel Secondary/Configurable Control Schematics

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

Ignition ON, observe the scan tool Steering Wheel Controls (SWC) Switch Voltage parameter. Pressing the switch should read voltage present, and drop to 0 volts when released.

1. Ignition OFF, disconnect the harness connector at the left and right steering wheel control switches.
2. Ignition ON, test for B+ between the voltage reference circuit terminal 1 and ground.

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

3. Test for B+ between the voltage reference circuit terminal 1 and the signal circuit terminals listed below:

•	Steering wheel control switch signal circuit terminal 5 - left switch.

•	Steering wheel control switch signal circuit terminal 6 - right switch.

⇒	If less than the specified value, test the signal circuits for a short to voltage or an open/high resistance. If the circuits test normal, replace the BCM.

4. Ignition OFF, disconnect the X1 harness connector at the BCM.
5. Test for infinite resistance between ground and the signal circuit terminals listed below:

•	Steering wheel control switch signal circuit terminal 5 - left switch.

•	Steering wheel control switch signal circuit terminal 6 - right switch.

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

6. Ignition ON, test for less than 1 volt between ground and the voltage reference circuit terminal 1 at the left steering wheel control switch.

⇒	If greater than the specified range, test the voltage reference circuit for a short to voltage

7. Ignition ON, test for infinite resistance between ground and the voltage reference circuit terminal 1 at the left steering wheel control switch.

⇒	If not the specified value, test the voltage reference circuit for a short to ground.

8. Test for less than 1 ohm between the voltage reference circuit terminal 1 at the left steering wheel control switch and the voltage reference circuit terminal 2 at the right steering wheel control switch.

⇒	If greater than the specified range, test the voltage reference circuit for a an open/high resistance.

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

1. Disconnect the harness connector at the right or left steering wheel control switch.
2. Connect a DMM between terminal 1 and terminal 5 (left switch) or terminal 6 (right switch) of either the left or right steering wheel control switches.

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.