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 provide an overview of each diagnostic category.

DTC Descriptor

DTC B3624: Steering Wheel Controls Entertainment Signal 2 Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

B+ Voltage Reference

1

1

1

--

10-Volt Reference

1

1

1

--

Steering Wheel Control Switch Signal

1

1

1

--

Steering Wheel Control Switch 2 Signal

B3624

1

1

B3624

1. Steering Wheel Controls Inoperative

Circuit/System Description

The body control module (BCM) supplies voltage to the MUTE/SEEK + multiple momentary contact switch and monitors the steering wheel control switch 2 signal circuit. Each switch state is associated with a set resistance value and when the switch is pressed, a specific voltage drops across the resistor unique to that switch.

Conditions for Running the DTC

    • Battery voltage is between 9-16 volts
    • The ignition is ON.

Conditions for Setting the DTC

    • The BCM detects a short to ground on the steering wheel controls 2 signal circuit.
    • The steering wheel controls 2 signal circuit remains in the same state for 1 minute.

Action Taken When the DTC Sets

The MUTE/SEEK + switch remains in the last selected position.

Conditions for Clearing the DTC

    • The conditions for setting the DTC are no longer present.
    • A history DTC clears after 100 malfunction-free ignition cycles.

Diagnostic Aids

This diagnostic is for the audio steering wheel controls for vehicles not equipped with RPO K59 adaptive cruise.

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 Data List

Control Module References for scan tool information

Circuit/System Testing

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

Component Testing

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

Seek

1.9k Ohms

2.1k Ohms

Mute

4.9k Ohms

5.1k Ohms

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