B2555

DTC B2555

DTC DESCRIPTOR

DTC B2555 05

Passenger Compartment Lamp Control Circuit Open or Short to Battery

DIAGNOSTIC FAULT INFORMATION






IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview

CIRCUIT/SYSTEM DESCRIPTION
The INTERIOR LIGHTS fuse supplies battery voltage to the body control module (BCM). The BCM applies battery voltage to the inside rearview mirror lamps through the courtesy lamp supply voltage circuit. The inside rearview mirror lamps are controlled by a 3 position (DOOR, OFF, ON) switch. When the inside rearview mirror switch is placed in the DOOR position, the lamps are controlled by the BCM. When any door is opened, the jam switch contacts close and the BCM receives a door-open input. If the BCM receives a door lock or unlock input or a rear hatch open input, the BCM will activate the courtesy lamp supply voltage circuit, providing battery voltage to the rearview mirror lamps. The BCM also provides ground to the inside rearview mirror lamps through the courtesy lamp control circuit.

CONDITIONS FOR RUNNING THE DTC
Battery voltage must be between 9-16 volts.

CONDITIONS FOR SETTING THE DTC
DTC B2555 05 will set when the BCM detects an open or short to voltage in the courtesy lamp control circuit.

ACTION TAKEN WHEN THE DTC SETS
When DTC B2555 05 is present, the inside rearview mirror lamps will only operate manually with the inside rearview mirror lamp switches.

CONDITIONS FOR CLEARING THE DTC
- The condition responsible for setting the DTC no longer exists.
- You issue a scan tool CLEAR DTCs command.
- A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

Circuit/System Testing
1. Disconnect the inside rearview mirror harness connector.
2. Connect a test lamp between the courtesy lamp control circuit and ground at the inside rearview mirror harness connector.
- If the test lamp illuminates, locate and repair a short to voltage in the courtesy lamp control circuit.
- If the test lamp does not illuminate, locate and repair an open or high resistance in the courtesy lamp control circuit.

3. If circuits test OK, replace the BCM.

Repair Instructions

IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

Control Module References for BCM replacement, setup, and programming Programming and Relearning