Steering Wheel Controls Inoperative

Steering Wheel Controls Inoperative

Diagnostic Instructions

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



Circuit/System Description

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


Diagnostic Aids

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


Reference Information
Schematic Reference

Steering Wheel Secondary/Configurable Control Schematics (Steering Wheel Secondary/Configurable Control Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Steering Wheel Controls Description and Operation (Steering Wheel Controls Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning)


Circuit/System Verification

Ignition ON, observe the scan tool steering wheel control (SWC) Bank 1 status. While pressing and releasing the switches. The reading should be SW1-SW10 identifying the switch pressed and Idle when released.


Circuit/System Testing

Important: It is recommended that Component Testing is performed before Circuit Testing when diagnosing steering wheel controls.


Caution: Refer to SIR Caution (SIR Caution) .

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 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. Test for 0 volts between the signal circuit terminal 4 and ground.

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

4. Test for ignition voltage between the ignition circuit terminal 3 and the signal circuit terminal 4.

• If less than the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, test or replace the switch.



Component Testing
Caution: Refer to SIR Caution (SIR Caution) .

1. Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
2. Test the for less than 2,800 ohms between the ignition circuit terminal 1 and the signal circuit terminal 5.

• If not the specified range, replace the steering wheel control switch.

3. Test for infinite resistance between the ignition circuit terminal 1 and the signal terminal 2 with the switch in the open position.

• If not the specified range, replace the steering wheel control switch.

4. Test the for less than 2,800 ohms between the ignition circuit terminal 1 and the signal terminal 2 with the switch in the closed position.

• If greater than the specified range, replace the steering wheel control switch.




Repair Instructions

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

* Steering Wheel Control Switch Assembly Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for BCM replacement, setup, and programming