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 Descriptor

DTC B0005: In Park Switch Signal Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Park Brake Switch Signal

B0005

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Circuit/System Description

The body control module (BCM) monitors the park brake switch via the park brake switch signal circuit. With the park brake applied, the switch is closed and the signal circuit is grounded. The BCM will then send a serial data message to the instrument panel cluster (IPC) requesting the red brake warning indicator be illuminated.

Conditions for Running the DTC

Ignition is ON.

Conditions for Setting the DTC

The BCM detects the park brake switch signal is grounded and the vehicle speed is greater than 5 km/h (8 mph).

Action Taken When the DTC Sets

The red brake warning indicator is illuminated.

Conditions for Clearing the DTC

    • A current DTC will clear when the condition for setting the DTC is no longer present.
    • A history DTC will clear after 100 malfunction-free ignition cycles.

Reference Information

Schematic Reference

Hydraulic Brake Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Brake Warning System 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

Observe the scan tool BCM Park Brake Switch parameter while applying and releasing the park brake. The parameter should cycle between Applied and Release.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the park brake switch.
  2. Ignition ON, verify the scan tool BCM Park Brake Switch parameter is Released.
  3. If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the BCM.
  4. Install a 3A fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool BCM Park Brake Switch parameter is Applied.
  5. If not 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. If all circuits test normal, test or replace the park brake switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Parking Brake Indicator Switch Replacement
    •  Control Module References for BCM replacement, setup, and programming