Steering Wheel Controls Inoperative

Steering Wheel Controls Inoperative

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

The body control module (BCM) supplies voltage to the audio steering wheel control switches and monitors the return signal. The steering wheel control switch is a multiplexed momentary contact switch. Each switch state is associated to a set resistance value and when pressed, a specific voltage drops across the resistor unique to that switch. The BCM identifies the switch selection and sends a serial data message to the component controlled by the switch and activates the feature.

Diagnostic Aids

* If a single switch function is inoperative, test the suspect switch.
* The resistance value for the individual steering wheel control switches (right) should be within the listed resistance values below:






Circuit/System Verification

* Ensure the primary controls of the associated component are functioning properly.
* Ignition ON, observe the scan tool SWC Bank 1 parameter while pressing and releasing the right steering wheel control switches. The parameter should display SW1-SW10 corresponding to the switch pressed and Idle when the switch is released.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
2. Ignition ON, test for ignition voltage between the ignition circuit terminal 3 and ground.

• If greater than the specified value, test the ignition circuit for a short to voltage. If the circuit tests normal, replace the BCM.

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

3. Verify the scan tool SWC Bank 1 parameter is Idle.

• If not the specified value, test the signal circuit terminal 4 for a short to voltage. If the circuit tests normal, replace the BCM.

4. Ignition OFF, connect the harness connector at the right steering wheel controls switch assembly.
5. Ignition ON, while pressing and releasing each of the right steering wheel control switches, observe the scan tool SWC Bank 1 parameter. The SWC Bank 1 parameter should display a value corresponding to SW 1 - SW 10 for each of the right steering wheel control switches pressed.

• If not the specified value, test the signal circuit terminal 4 for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the right steering wheel controls switch.

6. If all circuits test normal, test or replace the BCM

Component Testing

1. Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
2. Test for infinite resistance between the ignition terminal 3 and the signal terminal 6 with the switch in the open position.

• If less than specified value, replace the switch.

3. Test for less than 5,400 ohms between the ignition terminal and the signal terminal with the switch closed in each position.

• If greater than the specified range, replace the switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Steering Wheel Control Switch Assembly Replacement