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 each diagnostic category.
DTC Descriptor
DTC B1480 00
- Battery Rundown Protection Circuit
Diagnostic Fault Information
Circuit/System Description
The body control module (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. 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
The BCM detects a short ground in the inadvertent power courtesy lamp control circuit.
Action Taken When the DTC Sets
The BCM will deactivate inadvertent power to the courtesy lamps.
Conditions for Clearing the DTC
* The condition responsible for setting the DTC no longer exists.
* 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 X3 harness connector at the BCM.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
3. Ignition OFF, connect the X3 harness connector at the BCM.
4. Disconnect the harness connector at each component listed below:
* Dome/reading Lamp
* Left Vanity Mirror Lamp
* Right Vanity Mirror Lamp
* Reading Lamp Assembly
* Inside Rearview Mirror Lamp
* Rear Compartment Courtesy Lamp
5. Ignition ON, verify that a test lamp illuminates between the control circuit at each component harness connector 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 circuits test normal, replace the BCM.
6. Connect each component one at a time and verify with a scan tool if the DTC resets as current.
• If the DTC resets, test or replace the inoperative component.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Headlamp Switch Replacement (Impala) (Service and Repair)
* Sunshade Illuminated Mirror Lamp Bulb Replacement (Sunshade Illuminated Mirror Lamp Bulb Replacement)
* Sunshade Replacement (Service and Repair)
* Instrument Panel Courtesy Lamp Bulb Replacement (Instrument Panel Courtesy Lamp Bulb Replacement)
* Dome Lamp Replacement (Impala) (Service and Repair)
* Inside Rearview Mirror Replacement (Inside Rearview Mirror Replacement)
* Rear Compartment Courtesy Lamp Replacement (Rear Compartment Courtesy Lamp Replacement)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming