GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B1480 00: Battery Rundown Protection Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Dome Lamp Switch Signal

2

2

2

--

Courtesy Lamp Control

B1480 00

1, 2

--

--

Courtesy Lamp Control - Left Door

2

2

2

--

Courtesy Lamp Control - Right Door

2

2

2

--

Courtesy Lamp Switch - Console Control

2

2

--

--

Courtesy Lamp Low Control

2

1, 2

1, 2

--

Courtesy Lamp - Left Door Ground

--

2

--

--

Courtesy Lamp - Right Door Ground

--

2

--

--

Courtesy Lamp Switch - Console Ground

--

2

--

--

Driver Information Center (DIC) Switch Ground

--

2

--

--

I/P Compartment Lamp Ground

--

2

--

--

Rear Compartment Lid Latch Assembly Ground

--

2

--

--

Rear Compartment Lid Pull Down Actuator Ground

--

2

--

--

Underhood Lamp Ground

--

2

--

--

Vanity Mirror Lamp - Right Ground

--

2

--

--

Vanity Mirror Lamp - Left Ground

--

2

--

--

1. Rearview Mirror Lamp(s) Inoperative - Inside

2. Courtesy Lamps Malfunction

Circuit/System Description

The INTERIOR LIGHTS 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, rearview mirror lamps, and rear compartment lamps. The BCM also provides a serial data message to the driver door module (DDM) and passenger door module (PDM) to apply battery voltage to the exterior courtesy lamps. In the event that any of these lamps were to remain illuminated for more than 10 minutes with the ignition switch in the OFF position, the BCM will deactivate the courtesy lamp supply voltage 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, underhood lamp, IP compartment lamp, console lamp and both visor vanity mirror lamps is shorted to ground for longer than 1 second.

Actions Taken When the DTC Sets

The courtesy lamps, underhood lamp, I/P compartment lamp, console lamp, and both visor vanity mirror lamps will not operate.

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

Connector End View Reference

Component Connector End Views

Description and Operation

Interior Lighting Systems Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

  1. Ignition OFF, disconnect the appropriate harness connector at each component fed by the courtesy lamp control circuit.
  2. Ignition ON, verify that a test lamp illuminates between the courtesy lamp control circuit at each component harness connector and ground.
  3. 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.
  4. Connect each component one at a time and verify with a scan tool if the DTC resets as current.
  5. If the DTC resets, test or replace the inoperative component.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Instrument Panel Courtesy Lamp Bulb Replacement
    •  Underhood Lamp Replacement
    •  Cargo Lamp Replacement
    •  Inside Rearview Mirror Replacement
    •  Sunshade Replacement
    •  Control Module References for BCM replacement, setup, and programming