Steering Wheel Controls Inoperative

Steering Wheel Controls Inoperative

Diagnostic Fault Information

Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection





Circuit/System Description
The radio supplies 10 volts to the steering wheel control momentary contact switches, and monitors the return signal. Each switch is associated to a set resistance value, when pressed, a specific voltage drop occurs through a series of resistors unique to the switch selected. The radio will perform the desired function, or send a serial data message to its associated component.

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 Schematics
Connector End View Reference
^ Entertainment Connector End Views
^ Steering Wheel and Column Connector End Views

Electrical Information Reference
^ Circuit Testing
^ Connector Repairs
^ Testing for Intermittent Conditions and Poor Connections
^ Wiring Repairs

Circuit/System Testing

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

Caution: Refer to Restraint System Service Precautions.

1. Ignition OFF, disconnect the harness connector at the steering wheel control switches.
2. Ignition ON, radio ON, test for 9.8 - 10.2 volts between the 10-volt reference circuit and ground.
^ If less than 9.8 volts, test the 10-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.
^ If greater than 10.2 volts, test the 10-volt reference circuit for a short to voltage. If the circuit tests normal, replace the radio.

3. Ignition OFF, disconnect the harness connector at the radio, test for infinite resistance between the signal circuit and ground.
^ If less than infinite resistance, test the signal circuit for a short to ground.

4. Ignition OFF, test the signal circuit for less than 1.0 ohm of resistance between the radio and switch.
^ If greater than 1.0 ohm, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the radio.
5. If all circuits test normal, test or replace the switch.

Component Testing

Caution: Refer to Restraint System Service Precautions.

1. Ignition OFF, disconnect the harness connector at the steering wheel control switch.
2. Test for infinite resistance between the 10-volt reference terminal and the signal terminal with the switch in the open position.
^ If less than infinite resistance, replace the switch.

3. Test the resistance values between the 10-volt reference terminal and the signal terminal and with the switch in the closed position.
^ If values do not equal listed below, replace the switch.





Repair Instructions

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

^ Steering Wheel Control Switch Assembly Replacement
^ Control Module References for Radio replacement, setup, and programming.