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 steering wheel control switches duplicate the function of the primary controls of the associated cellular, entertainment and navigation (radio) component, through a network of momentary contact switches and a series of resistors. Depending on the vehicle cellular, entertainment and navigation (radio) option, a serial data gateway module (up level radio) or a standard radio (base radio) supplies voltage to the switches and monitors the return signals. When a switch is pressed, a specific voltage drops across the resistor unique to that switch. For the up level radio, the serial data gateway module identifies the switch selected and sends a serial data message to the cellular, entertainment and navigation (radio) component controlled by the switch, activating that feature. For the standard radio, the radio identifies the switch selected and activates the selected cellular, entertainment and navigation (radio) feature.
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 (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Ignition ON, cellular, entertainment and navigation (radio) ON.
2. Press and/or scroll each of the buttons on the radio control switch.
3. The cellular, entertainment and navigation (radio) should respond to desired function of the radio switch.
4. Ignition ON, observe the DTC information with a scan tool. Verify no DTCs are set.
• If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle).
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the S70R steering wheel control switch-right.
2. Ignition ON, test for B+ between the B+ circuit terminal 1 and ground.
• If less than the specified value, test the circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
3. Test for B+ between the B+ circuit terminal 1 and the signal circuit terminal 2.
• If less than the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
4. Ignition OFF, disconnect the X3 harness connector at the K9 BCM.
5. Test for infinite resistance between the signal circuit terminal 8 and ground.
• If less than the specified value, test the signal circuit for a short to ground.
6. If all circuits test normal, test or replace the S70R steering wheel control switch-right.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
Control Module References (Programming and Relearning) for serial data gateway module or radio replacement, programming and setup