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 B2555 00: Passenger Compartment Lamp Control Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Courtesy Lamp High Control

B2555 00

1

B2555 00

--

1. Courtesy Lamps Inoperative

Circuit/System Description

The CTSY fuse in the I/P fuse block supplies B+ to the body control module (BCM). When the BCM receives a door open signal and the courtesy defeat switch is not active, the BCM supplies B+ to the courtesy lamps. The courtesy lamps are grounded at G302, G401, and G402.

Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

    • DTC B2555 00 will set when the BCM detects a short to voltage in the courtesy lamp control circuit.
    • DTC B2555 00 will set when the BCM detects a short to ground in the courtesy lamp control circuit.

Action Taken When the DTC Sets

DTC B2555 00 is present, when a short to ground or short to voltage on the courtesy lamp control circuit is present.

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

Interior Lights Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Interior Lighting Systems 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 Testing

  1. Disconnect the harness connector at the cargo lamp.
  2. Connect a test lamp between the courtesy lamp high control circuit terminal C and ground.
  3. If the test lamp illuminates, locate and repair a short to voltage in the courtesy lamp high control circuit.
    If the test lamp does not illuminate, locate and repair a short to ground in the courtesy lamp high control circuit.
  4. If all circuits test normal, replace the BCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup, and programming