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 |
|---|---|---|---|---|
Remote Radio Control Supply Voltage | B1397 | 1 | 1 | -- |
Remote Radio Control Signal | 1 | 1 | B2815 | -- |
1. Steering Wheel Controls Inoperative | ||||
Circuit/System Description
The body control module (BCM) supplies voltage to the audio steering wheel control multiple momentary contact switches and monitors the return signal. Each switch is associated to a set resistance value, when pressed a specific voltage drop occurs through a series of resistors unique to that switch. The BCM identifies the selection, then sends a serial data message that is received by the component controlled, activating the feature.
Diagnostic Aids
| • | 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. |
| • | A poor connection at the right switch could cause the left switch to malfunction or be inoperative. |
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
Circuit/System Verification
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.
Circuit/System Testing
Important: It is recommended that Component Testing be performed before Circuit Testing when diagnosing steering wheel controls.
Caution: Refer to SIR Caution in the Preface section.
- Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
- Ignition ON, test for ignition voltage between the ignition circuit terminal 1 and ground.
- Test for ignition voltage between the ignition circuit terminal 1 and the signal circuit terminal 6.
- Install a 3A fused jumper wire between the ignition circuit terminal 1 and the signal circuit terminal 2.
- Disconnect the harness connector at the left steering wheel control switch.
- Test for ignition voltage between the signal circuit terminal 1 and ground.
- Test for ignition voltage between the between the signal circuit terminal 1 and the signal circuit terminal 5.
- Ignition OFF, disconnect the C3 harness connector at the BCM.
- Test for infinite resistance between the signal circuit terminal A2 and ground.
- If all circuits test normal, test or replace the switch.
| ⇒ | If less than the specified value, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If greater than the specified value, test the ignition circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
| ⇒ | If less than the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If greater than the specified value, test the signal circuit for a short to voltage |
| ⇒ | If less than the specified value, test the signal circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
| ⇒ | If less than the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
| ⇒ | If less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the BCM. |
Component Testing
Caution: Refer to SIR Caution in the Preface section.
- Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
- Test the for less than 2,400 ohms between the ignition terminal 1 and the signal terminal 2.
- Test for infinite resistance between the ignition terminal 1 and the signal terminal 6 with the switch in the open position.
- Test the for less than 2,400 ohms between the ignition terminal 1 and the signal terminal 6 with the switch in the closed position.
- Disconnect the harness connector at the left steering wheel control switch.
- Test for infinite resistance between the signal terminal 1 and the signal terminal 5 with the switch in the open position.
- Test for less than 12,000 ohms between the signal terminal 1 and the signal terminal 5 with the switch in the closed position.
| ⇒ | If greater than the specified range, replace the steering wheel control switch. |
| ⇒ | If not the specified value, replace the steering wheel control switch. |
| ⇒ | If greater than the specified value, replace the right steering wheel control switch. |
| ⇒ | If not the specified value, replace the steering wheel control switch. |
| ⇒ | If greater than the specified range, replace the steering wheel control switch. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
