B1480

DTC B1480

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions 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 hatch 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. For more detailed information concerning courtesy lamp operation refer to Interior Lighting Systems Description and Operation.

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, overhead console lamp, liftgate lamp and rear dome lamp is 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.

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 after completing the diagnostic procedure. Verification Tests

* Cargo Lamp Replacement
* Dome Lamp Replacement
* Vanity Mirror Lamp Replacement
* Instrument Panel Dimmer Switch Replacement (Left Hand Drive) Instrument Panel Dimmer Switch Replacement (Right Hand Drive)
* Overhead Console Courtesy Lamp Replacement
* Instrument Panel Courtesy Lamp Bulb Replacement - Left Side (Left Hand Drive) Instrument Panel Courtesy Lamp Bulb Replacement - Left Side (Right Hand Drive)
* Instrument Panel Courtesy Lamp Bulb Replacement - Right Side (Left Hand Drive) Instrument Panel Courtesy Lamp Bulb Replacement - Right Side (Right Hand Drive)
* Rear Liftgate Lamp Replacement
* Control Module References for BCM replacement, setup, and programming. Programming and Relearning