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
LINK
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.
| • | Steering Wheel Control Switch Assembly Replacement |
| • | Control Module References for BCM replacement, setup, and programming |
