• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
B+ Voltage Reference | B1397 | 1 | -- | B2815 |
Steering Wheel Control Switch Signal | 1 | 1 | 1 | -- |
1. Steering Wheel Controls Inoperative |
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.
• | Battery voltage is between 9-16 volts |
• | The ignition is ON. |
The BCM senses a short to ground in the voltage circuit for more than 1 second.
The BCM senses a switch voltage that is higher than normal.
The BCM will ignore switch inputs.
• | The condition responsible for setting the DTC no longer exists. |
• | A history DTC will clear once 100 consecutive malfunction free ignition cycles have occurred. |
Steering Wheel Secondary/Configurable Control Schematics
Steering Wheel Controls Description and Operation
Control Module References for Scan Tool Information
Ignition ON, observe the scan tool Steering Wheel Controls (SWC) Switch Voltage parameter. Pressing the switch should read voltage present, and drop to 0 volts when released.
⇒ | 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. |
• | Steering wheel control switch signal circuit terminal 5 - left switch. |
• | Steering wheel control switch signal circuit terminal 6 - right switch. |
⇒ | If less than the specified value, test the signal circuits for a short to voltage or an open/high resistance. If the circuits test normal, replace the BCM. |
• | Steering wheel control switch signal circuit terminal 5 - left switch. |
• | Steering wheel control switch signal circuit terminal 6 - right switch. |
⇒ | If less than the specified value, test the signal circuits for a short to ground. |
⇒ | If greater than the specified range, test the voltage reference circuit for a short to voltage |
⇒ | If not the specified value, test the voltage reference circuit for a short to ground. |
⇒ | If greater than the specified range, test the voltage reference circuit for a an open/high resistance. |
⇒ | If any of the resistance measurements for the individual switches are not within the specified resistance values, replace the left or right steering wheel control switch. |
Function Switch | Minimum Resistance Value | Maximum Resistance Value |
---|---|---|
Mute/Voice Recognition | 615 Ohms | 815 Ohms |
Program | 1.7k Ohms | 2.1k Ohms |
Source Down | 4.1k Ohms | 4.5k Ohms |
Source Up | 11.0k Ohms | 11.4k Ohms |
No Switch Pressed | O.L. | O.L. |
Function Switch | Minimum Resistance Value | Maximum Resistance Value |
---|---|---|
Volume Up | 1.1k Ohms | 1.3k Ohms |
Volume Down | 1.4k Ohms | 1.8k Ohms |
Seek Up | 1.7k Ohms | 2.1k Ohms |
Seek Down | 2.2k Ohms | 2.6k Ohms |
No Switch Pressed | O.L. | O.L. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, setup, and programming |