Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | 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 | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
10-Volt Reference | 1 | 1 | 1 | -- |
Right Steering Wheel Control Switch Signal | 1 | 1 | 1 | -- |
1. Steering Wheel Controls Inoperative | ||||
Circuit/System Description
The radio 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 radio identifies the switch selection and activates the feature.
Diagnostic Aids
Before diagnosis of the steering wheel controls, ensure the primary controls of the associated component are functioning properly.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Steering Wheel Controls Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
- Ignition ON, radio ON, test for 9.8-10.2 volts between the voltage reference circuit terminal 2 and ground.
- Test for greater than 9 volts between the voltage reference circuit terminal 2 and the signal circuit terminal 4.
- Ignition OFF, disconnect the X1 harness connector at the radio.
- Test for infinite resistance between the signal circuit terminal 4 and ground.
- If all circuits test normal, test or replace the right steering wheel control switch.
| ⇒ | If greater than the specified range, test the voltage reference circuit for a short to voltage. If the circuit tests normal, replace the radio. |
| ⇒ | If less than the specified range, test the voltage reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio. |
| ⇒ | If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the radio. |
| ⇒ | If less than the specified value, test the signal circuit for a short to ground. |
Component Testing
- Disconnect the harness connector at the right steering wheel control switch.
- Connect a DMM between terminals 2 and 4 of the right steering wheel control switch.
| ⇒ | If any of the resistance measurements for the individual switches are not within the specified resistance values, replace the right steering wheel control switch. |
Function Switch | Minimum Resistance Value | Maximum Resistance Value |
|---|---|---|
Volume Up | 1.1k Ohms | 1.5k Ohms |
Volume Down | 1.4k Ohms | 1.8k Ohms |
Next | 1.7k Ohms | 2.1k Ohms |
Previous | 2.2k Ohms | 2.6k Ohms |
Mute/Voice Activation | 2.9k Ohms | 3.3k Ohms |
No Switch Pressed | O.L. | O.L. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for radio replacement, setup, and programming |
