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 |
|---|---|---|---|---|
12 Volt Reference | B1529 03 | 1 | -- | B1529 05 |
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.
Conditions for Running the DTC
| • | Battery voltage is between 9 V and 16 V. |
| • | The ignition is ON. |
Conditions for Setting the DTC
The BCM detects a short to voltage in the steering wheel control switch signal circuit.
Action Taken When the DTC Sets
The BCM will ignore switch inputs.
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 Testing
- Ignition OFF, disconnect the X1 harness connector at the X85 Inflatable Restraint Steering Wheel Module Coil.
- Ignition ON, test for greater than 11 V between the voltage reference circuit terminal 5 (X1) and ground.
- Test for greater than 11 V between the voltage reference circuit terminal 5 (X1) and the signal circuit terminal 4 (X1).
- Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module (BCM).
- Test for infinite resistance between the signal circuit terminal 4 (X1) at the X85 Inflatable Restraint Steering Wheel Module Coil and ground.
- If all circuits test normal, test or replace the S70R Steering Wheel Control Switch-Right.
| ⇒ | 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 K9 Body Control Module (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 K9 Body Control Module (BCM). |
| ⇒ | If less than the specified value, test the signal circuit for a short to ground. |
Component Testing
Static Test
- Disconnect the harness connector at the X85 Inflatable Restraint Steering Wheel Module Coil.
- Test the resistance between the terminals 4 (X1) and 5 (X1) of the X85 Inflatable Restraint Steering Wheel Module Coil.
| ⇒ | If any of the resistance measurements for the individual switches are not within the specified resistance values, replace the S70R Steering Wheel Control Switch-Right. |
Function Switch | Minimum Resistance Value | Maximum Resistance Value |
|---|---|---|
Volume Down | 1.0 kΩ | 1.4 kΩ |
Volume Up | 1.3 kΩ | 1.7 kΩ |
Seek Down | 1.7 kΩ | 2.1 kΩ |
Seek Up | 2.2 kΩ | 2.6 kΩ |
Source | 2.8 kΩ | 3.2 kΩ |
Phone / Push to Talk | 3.6 kΩ | 4.0 kΩ |
Hang Up / Audio Mute | 5.1 kΩ | 5.5 kΩ |
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 |
