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 |
|---|---|---|---|---|
B+ Voltage Reference | B1529 03 | 1 | -- | B1529 07 |
Right Steering Wheel Control Switch Signal | 1 | 1 | B3622 07 | -- |
1. Steering Wheel Controls Inoperative | ||||
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
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 Verification
Ignition ON, observe the scan tool SWC Bank 1 status while pressing and releasing the switches. The reading should be SW1-SW7 identifying the switch pressed, and Idle when released.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
- Ignition ON, test for B+ between the voltage reference circuit terminal 3 and ground.
- Test for B+ between the voltage reference circuit terminal 3 and the signal circuit terminal 4.
- Ignition OFF, disconnect the X1 harness connector at the BCM.
- 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 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 BCM. |
| ⇒ | 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 BCM. |
| ⇒ | 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 3 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 |
|---|---|---|
Mute/Voice Recognition | 1.0k Ohms | 1.4k Ohms |
Volume Down | 1.3k Ohms | 1.7k Ohms |
Volume Up | 1.7k Ohms | 2.1k Ohms |
Previous | 2.2k Ohms | 2.6k Ohms |
Next | 2.8k Ohms | 3.2k Ohms |
Source | 3.6k Ohms | 4.0k Ohms |
Seek | 5.1k Ohms | 5.5k Ohms |
No Switch Pressed | O.L. | O.L. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
