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

TBC 4 Battery Supply

B1480

B1480

--

--

Inadvertent Power Supply

B1480

1

--

--

1. Reading and Vanity Mirror Lamps Malfunction

Circuit/System Description

The body control module (BCM) supplies battery positive voltage to the reading lamps and both visor vanity mirror 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 lamps supply voltage circuit to prevent a total battery discharge condition

Conditions for Running the DTC

The battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

    • The TBC 4 fuse battery supply circuit to the BCM is open or shorted to ground.
    • The inadvertent power supply voltage circuit to the reading and vanity mirror lamps is shorted to ground.

Action Taken When the DTC Sets

The reading and vanity mirror lamps will be inoperative.

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

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 BCM connector X3.
  2. Verify that a test lamp illuminates between the B+ circuit terminal B17 and ground.
  3. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, and the B+ circuit fuse is open, test the inadvertent power supply circuit terminal B18 for a short to ground.
  4. If the circuits test normal, replace the BCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, programming, and setup