For 1990-2009 cars

### 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.

### DTC Descriptors

DTC B1529 03: Device Voltage Reference Output Circuit Voltage Below Threshold
DTC B1529 07: Device Voltage Reference Output Circuit Voltage Above Threshold

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
B+ Voltage Reference | B1529 03 | 1 | -- | B1529 07
Right 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 9-16 volts

• | The ignition is ON.

### Conditions for Setting the DTC

#### B1529 03

• | The BCM detects a short to ground in the B+ voltage reference circuit.

• | The above condition is present for greater than 30 seconds.

#### B1529 07

• | The BCM detects a short to voltage in the B+ voltage reference circuit.

• | The above condition is present for greater than 30 seconds.

### Action Taken When the DTC Sets

The BCM will ignore switch inputs.

### Conditions for Clearing the DTC

• | The condition responsible for setting the DTC no longer exists.

• | A history DTC will clear once 100 consecutive malfunction free ignition cycles have occurred.

### Reference Information

#### Schematic Reference

Steering Wheel Secondary/Configurable Control Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Steering Wheel Controls Description and Operation

#### 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

Ignition ON, 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

1. Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
2. Ignition ON, test for B+ between the voltage reference circuit terminal 3 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 BCM.

3. Test for B+ between the voltage reference circuit terminal 3 and the signal circuit terminal 4.

⇒ | 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 BCM.

4. Ignition OFF, disconnect the X1 harness connector at the BCM.
5. Test for infinite resistance between the signal circuit terminal 4 and ground.

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

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

### Component Testing

1. Disconnect the harness connector at the right steering wheel control switch.
2. Connect a DMM between terminals 3 and 4 of the right steering wheel control switch.

⇒ | If any of the resistance measurements for the individual switches are not within the specified resistance values, replace the right steering wheel control switch.

Function Switch | Minimum Resistance Value | Maximum Resistance Value
--- | --- | ---
Mute/Voice Recognition | 1.0k Ohms | 1.4k Ohms
Volume Down | 1.3k Ohms | 1.7k Ohms
Volume Up | 1.7k Ohms | 2.1k Ohms
Previous | 2.2k Ohms | 2.6k Ohms
Next | 2.8k Ohms | 3.2k Ohms
Source | 3.6k Ohms | 4.0k Ohms
Seek | 5.1k Ohms | 5.5k Ohms
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