Service Information

Volt

Steering Wheel Controls Malfunction

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	1	1	--	--
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 reindicator. 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

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Vehicle in Service Mode, 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

Vehicle OFF, disconnect the harness connector at the S70R steering wheel control switch - right.
Vehicle in Service Mode, test for B+ between the voltage reference circuit terminal 1 and ground.

⇒	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.

Test for B+ between the voltage reference circuit terminal 1 and the signal circuit terminal 2.

⇒	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.

Vehicle OFF, disconnect the X3 harness connector at the K9 body control module.
Test for infinite resistance between the signal circuit terminal 2 and ground.

⇒	If less than the specified value, test the signal circuit for a short to ground.

If all circuits test normal, test or replace the S70R steering wheel control switch - right.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Radio and Telephone Control Switch Replacement

•	Control Module References for BCM replacement, programming and setup