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 radio 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 the resistor unique to that switch. The radio identifies the switch selection and activates the feature. Otherwise, the radio sends a serial data message to the component controlled by the switch and activates the feature.


Diagnostic Aids

* This diagnostic is for the audio steering wheel controls.
* Before diagnosis of the steering wheel controls, ensure the primary controls of the associated component are functioning properly.
* If a single switch function is inoperative, test the suspect switch. Refer to component testing.



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


Scan Tool Reference

Control Module References (Programming and Relearning)


Circuit/System Verification

Ignition ON, Radio ON, observe the scan tool Volume Control parameter. The reading should increase percentage or decrease percentage while pressing the volume up or down button.


Circuit/System Testing

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



1. Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
2. Ignition ON, radio ON, test for 7.5-8.5 volts between the ignition circuit terminal 2 and ground.

• If less than the specified range, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.
• If greater than the specified range, test the ignition circuit for a short to B+. If the circuit tests normal, replace the radio.

3. Test for 7.5-8.5 volts between the ignition circuit terminal 2 and the signal circuit terminal 4.

• If less than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the radio.
• If greater than the specified range, test the signal circuit for a short to B+. If the circuit tests normal, replace the radio.

4. Ignition OFF, disconnect the X1 harness connector at the radio.
5. Test for infinite resistance between the signal circuit terminal A7 and ground.

• If not the specified value, test the signal circuit for a short to ground. If the circuit tests normal, test or replace the switch.

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



Component Testing

1. Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
2. Test for infinite resistance between the signal terminal 4 and the ignition terminal 2 with the switch in the open position.

• If not the specified value, replace the switch.

3. Test for less than 3200 ohms between the signal circuit terminal and the ignition circuit terminal with the switch in the closed position.

• If greater than the specified range, replace the 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 Radio replacement, setup, and programming