GM Service Manual Online
For 1990-2009 cars only

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 BCM SWC Bank 1 Status parameter. The reading should be idle and change between SW1-SW7 when pushing the appropriate switch.

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.
  3. 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.
  4. Test for B+ between the voltage reference circuit terminal 3 and the signal circuit terminal 4.
  5. 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.
  6. Ignition OFF, disconnect the X1 harness connector at the BCM.
  7. Test for infinite resistance between the signal circuit terminal 4 and ground.
  8. If less than the specified value, test the signal circuit for a short to ground.
  9. If all circuits test normal, test or replace the right steering wheel control switch.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the right steering wheel control switch.
  2. Test the resistance between the voltage reference terminal 3 and the signal terminal 4 while depressing the appropriate steering wheel controls switch listed below.
  3. If not the specified range, replace the steering wheel 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