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 each diagnostic category.

DTC Descriptor
DTC B1480 00
- Battery Rundown Protection Circuit No Additional Information

Diagnostic Fault Information





Circuit/System Description

The INT LIGHT fuse supplies battery voltage to the inadvertent load control relay located in the body control module (BCM). The BCM applies ground to the inadvertent relay control circuit which energizes the inadvertent load control relay coil. With the relay coil energized, the switch contacts close allowing battery voltage to flow from the INT LIGHT fuse to the inside rearview mirror lamps through the inside rearview mirror lamps supply voltage circuit. The inside rearview mirror lamps are controlled by a 3 position (OFF, DOOR, ON) switch. When the inside rearview mirror switch is placed in the DOOR position, the lamps are controlled by the BCM by grounding the courtesy lamp control 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, the BCM will activate the inadvertent relay control circuit, providing battery voltage to the inside rearview mirror lamps. The BCM also provides ground to the inside rearview mirror lamps through the courtesy lamp control circuit.

Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

The courtesy lamps voltage supply circuit is shorted to ground for 1 second or greater.

Action 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 harness connector at the inside rearview mirror.
2. Ignition ON, verify that a test lamp illuminates between the inside rearview mirror lamps supply voltage circuit and ground.

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

3. Connect the inside rearview mirror harness connector.
4. Verify with a scan tool that the DTC does not reset as current.
5. If the DTC resets, test or replace the inside rearview mirror.

Repair Instructions

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

* Rearview Mirror Replacement
* Control Module References for BCM replacement, setup, and programming Programming and Relearning