B1480

DTC B1480

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of the diagnostic category.



DTC Descriptor
DTC B1480 00
- Battery Rundown Protection Circuit




Diagnostic Fault Information






Circuit/System Description

The CTSY/LAMP fuse supplies battery voltage to the body control module (BCM). The BCM applies battery voltage to the courtesy lamps through the courtesy lamp supply voltage circuit. 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 compartment open input, the BCM will activate the courtesy lamp supply voltage circuit, providing battery voltage to all of the instrument panel (I/P) courtesy lamps, dome lamps, rearview mirror lamps, and rear compartment lamps. The BCM also provides a GMLAN serial data message to the driver door module (DDM) and front passenger door module (PDM) to apply battery voltage to the door courtesy lamps. In the event that any of these lamps were to remain illuminated for more than 20 minutes with the ignition switch in the OFF position, the BCM will deactivate the inadvertent power courtesy lamp control circuit to prevent a total battery discharge condition.


Conditions for Running the DTC

Battery voltage must be between 9-16 volts.


Conditions for Setting the DTC

DTC B1480 will set when the courtesy lamp supply voltage circuit that feeds the courtesy lamps, dome lamps, or overhead console lamps are shorted to ground for longer than 1 second.


Actions Taken When the DTC Sets

The courtesy lamps will not operate.


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.



Reference Information
Schematic Reference

Interior Lights Schematics (Interior Lights Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
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 Testing

1. Ignition OFF, disconnect the appropriate harness connector at each component fed by the inadvertent power courtesy lamp control circuit.
2. Ignition ON, verify that a test lamp illuminates between the inadvertent power courtesy lamp control circuit at each component harness connector and ground.

• If the test lamp does not illuminate, test the inadvertent power courtesy lamp control circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the BCM.

3. Connect each component one at a time and verify with a scan tool if the DTC resets as current.
4. If the DTC resets, test or replace the inoperative component.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Instrument Panel Courtesy Lamp Bulb Replacement (Instrument Panel Courtesy Lamp Bulb Replacement)
* Door Lamp Replacement (Door Lamp Replacement)
* Door Courtesy Lamp and Reflector Replacement (Door Courtesy Lamp and Reflector Replacement)
* Overhead Console Reading Lamp and Bulb Replacement (Service and Repair)
* Sunshade Illuminated Mirror Lamp Bulb Replacement (Sunshade Illuminated Mirror Lamp Bulb Replacement)
* Instrument Panel Flood Lamp Replacement - Left Side (Instrument Panel Flood Lamp Replacement - Left Side)
* Instrument Panel Flood Lamp Replacement - Right Side (Instrument Panel Flood Lamp Replacement - Right Side)
* Luminescent Lamp Replacement - Driver and Passenger Seat (Luminescent Lamp Replacement - Driver and Passenger Seat)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming