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Steering Wheel Controls Malfunction




Steering Wheel Controls Malfunction

Diagnostic Instructions

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

Diagnostic Fault Information






Circuit/System Description

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.

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 End Views By Name
Description and Operation

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

* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the S70L Steering Wheel Controls Switch - Left and the S70R Steering Wheel Controls Switch - Right.
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 K9 Body Control Module.

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

* Signal circuit terminal 6 - S70L Steering Wheel Controls Switch - Left
* Signal circuit terminal 2 - S70R Steering Wheel Controls Switch - Right

• If less than the specified value, test the signal circuits for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K9 Body Control Module.

4. Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module.
5. Test for infinite resistance between the signal circuit terminals listed below and ground.

* Signal circuit terminal 6 - S70L Steering Wheel Controls Switch - Left
* Signal circuit terminal 2 - S70R Steering Wheel Controls Switch - Right

• If less than the specified value, test the signal circuit for a short to ground.

6. Ignition ON, test for less than 0.3V between the signal circuit terminal 5 at the S70R Steering Wheel Controls Switch - Right and ground.

• If greater than the specified range, test the signal circuit for a short to voltage.

7. Test for infinite resistance between the signal circuit terminal 5 at the S70R Steering Wheel Controls Switch - Right and ground.

• If not the specified value, test the signal circuit for a short to ground.

8. Test for less than 5 ohm between the signal circuit terminal 5 at the S70R Steering Wheel Controls Switch - Right and the signal circuit terminal 5 at the S70L Steering Wheel Controls Switch - Left.

• If greater than the specified range, test the signal circuit for an open/high resistance.

9. If all circuits test normal, test or replace the S70R Steering Wheel Controls Switch - Right or S70L Steering Wheel Controls Switch - Left.

Component Testing
Static Test

Right Steering Wheel Switch
1. Disconnect the harness connector at the S70R Steering Wheel Controls Switch - Right.
2. Test the resistance between the terminals 1 and 2 of the S70R Steering Wheel Controls Switch - Right.

• If any of the resistance measurements for the individual switches are not within the specified resistance values, replace the S70R Steering Wheel Controls Switch - Right.





Left Steering Wheel Switch
1. Disconnect the harness connector at the S70L Steering Wheel Controls Switch - Left.
2. Test the resistance between the terminals 5 and 6 of the S70L Steering Wheel Controls Switch - Left.

• If any of the resistance measurements for the individual switches are not within the specified resistance values, replace the S70R Steering Wheel Controls Switch - Right.





Repair Instructions

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

* Radio Control Switch Replacement - Steering Wheel Radio Control Switch Replacement - Steering Wheel
* Control Module References Control Module References for BCM replacement, setup, and programming

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