B2558
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 Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC B2557
- Passenger Compartment Lamp Control Circuit Low
DTC B2558
- Passenger Compartment Lamp Control Circuit High
Diagnostic Fault Information
Circuit/System Description
B+ 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.
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
B2557
The courtesy lamp voltage reference 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 Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
Ignition ON, command the courtesy lamps On and Off with a scan tool.
If the courtesy lamps do not turn on or remain on at all times, perform the Courtesy Lamp Control Circuit Test.
Circuit/System Testing
Courtesy Lamp Control Circuit Test
1. Ignition OFF, disconnect the harness connector at the appropriate courtesy lamp.
2. Ignition ON, verify that a test lamp illuminates between the listed courtesy lamp supply circuit terminal and ground.
* Dome/Reading Lamps terminal B
* Dome Lamp terminal B
* I/P Courtesy Lamp - Left terminal A
* I/P Courtesy Lamp - Right terminal A
* Vanity Mirror Lamp - Left terminal A
* Vanity Mirror Lamp - Right terminal A
• If the test lamp does not illuminate, test the courtesy lamp supply 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 listed control circuit terminal and courtesy lamp supply circuit terminal.
* Dome/Reading Lamps terminal A and B
* Dome Lamp terminal A and B
* I/P Courtesy Lamp - Left terminal B and A
* I/P Courtesy Lamp - Right terminal B and A
* Vanity Mirror Lamp - Left terminal B and A
* Vanity Mirror Lamp - Right terminal B and A
4. Operate the courtesy lamp switch ON and OFF. 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.
5. If all circuits test normal, test or replace the appropriate bulb.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Dome Lamp Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, programming, and setup