B2557
DTC B2557 or B2558
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructionsprovides an overview of each diagnostic category.
DTC Descriptors
DTC B2557
- Passenger Compartment Lamp Control Circuit Low
DTC B2558
- Passenger Compartment Lamp Control Circuit High
Diagnostic Fault Information
Circuit/System Description
The interior courtesy lamps consist of the dome lamp, reading lamps, cargo lamps, and the left and right footwell lamps. Battery voltage is supplied to the courtesy lamps by the body control module (BCM) through an inadvertent power supply circuit. In the event that any of these lamps were to remain illuminated for a period of more than 20 minutes with the ignition switch in the OFF position, the BCM will deactivate the inadvertent power supply to prevent a total battery discharge condition. Courtesy lamp operation is controlled by the BCM through low side drive control circuits, and any time the inadvertent power supply is active the BCM turns on the courtesy lamps by grounding the control circuits. The BCM will activate the courtesy lamps using inputs from the dome lamp switch on the headlamp switch assembly or any of the door jamb switches. The dome lamp switch signal is monitored from battery voltage by the BCM and when the switch is turned on the signal circuit will be closed to the headlamp switch low reference circuit.
Conditions for Running the DTC
The battery voltage must be between 9-16 V.
Conditions for Setting the DTC
B2557
The courtesy lamp supply circuit is shorted to ground.
B2558
The courtesy lamp control circuit is shorted to voltage.
Action Taken When the DTC Sets
The courtesy lamps will not operate or will remain always on.
Conditions for Clearing the DTC
* This DTC will clear on current status after the condition for setting the fault is corrected.
* A history DTC will clear after 100 consecutive ignition cycles without a fault present.
Reference Information
Schematic Reference
Interior Lights Schematics Interior Lights Schematics
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
Interior Lighting Systems Description and Operation Interior Lighting Systems
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module Referencesfor scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the dome/reading lamps.
2. Ignition ON, verify that a test lamp illuminates between the signal circuit terminal B and ground.
• If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal , test or replace the BCM.
3. Connect a test lamp between the ground circuit terminal A and the signal circuit terminal B. Command the Courtesy Lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.
• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
4. If all circuits test normal, replace the dome/reading lamps.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Dome Lamp Replacement Service and Repair
* Dome Lamp Bulb Replacement Service and Repair
* Control Module References Control Module Referencesfor BCM replacement, setup, and programming