Steering Wheel Controls Inoperative (3-Spoke)
Steering Wheel Controls Inoperative (3-Spoke)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Diagnostic Fault Information
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 and when pressed a specific voltage drop across the resistor unique to the switch selected. The radio will perform the desired function or send a serial data message to the other component controlled by the switch.
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.
* Review with the schematic when testing switch resistance values.
* If a single switch function is inoperative, test the suspect switch. Refer to component testing.
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 right steering wheel control switch.
2. Ignition ON, Radio ON, test for 9.2-10 volts between the 10-volt reference circuit terminal 2 and ground.
• If less than the specified range, test the 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 circuit for a short to voltage. If the circuit tests normal, replace the radio.
3. Test for 9.2-10 volts between the 10-volt reference circuit terminal 2 and the signal circuit terminal 4.
• If less than the specified range, test the circuit for an open/high resistance. If the circuit tests normal, replace the radio.
• If greater than the specified range, test the circuit for a short to voltage. If the circuit tests normal, replace the radio.
4. Disconnect the X1 harness connector at the radio.
5. Test for infinite resistance between the signal circuit terminal A9 and ground.
• If not the specified value, test the signal circuit for short to ground.
6. If all circuits test normal, test or replace the steering wheel control switch.
Component Testing
Caution: Refer to Restraint System Service Precautions.
1. Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
2. Test for infinite resistance between the signal circuit terminal 4 and the 10-volt reference terminal 2 with the switch in the open position.
• If not the specified value, replace the right steering wheel control switch.
3. Test for less than 3,200 ohms of resistance between the signal circuit terminal 4 and the 10-volt reference terminal 2 with the switch in the closed position.
• If greater than the specified value, replace the right steering wheel control switch.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
* Steering Wheel Control Switch Assembly Replacement