B1480

DTC B1480

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B1480 02
- Battery Rundown Protection Circuit Short to Ground

Diagnostic Fault Information






Circuit/System Description

The body control module (BCM) supplies battery voltage to the front and rear reading lamps, left and right sunshade lamps, center console compartment lamp, and instrument panel compartment lamp via the courtesy lamp control circuit. When the instrument panel compartment or a sunshade mirror is opened, the switch contacts close allowing battery voltage to flow illuminating the respective lamps. The front and rear reading lamps are controlled by individual switches that are activated by the operator when additional cabin lighting is required. In the event that any of these courtesy lamps were to remain illuminated for more than 10 minutes with the ignition switch in the OFF position and no doors opened, the BCM will deactivate the courtesy lamp control circuit to prevent total battery discharge.

Conditions for Running the DTC

Battery voltage must be between 9-16 V.

Conditions for Setting the DTC

The BCM detects a short to ground in the courtesy lamps control circuit.

Actions Taken When the DTC Sets

The BCM will disable the circuit and all lamps controlled by the courtesy lamp control circuit will be inoperative.

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 Sunshade - Left

Description and Operation

Power Mode Description and Operation Power Mode

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Testing

1. Ignition OFF, exterior lamps OFF, disconnect the harness connectors at the components listed below.

* E27 instrument panel compartment lamp

* E31L sunshade - left

* E31R sunshade - right

* E37D dome/reading lamps - overhead console

* E37R dome/reading lamps - rear

2. Connect a test lamp between the appropriate control circuit terminal listed below and ground.

* E27 instrument panel compartment lamp terminal 1

* E31L sunshade mirror lamp - left terminal A

* E31R sunshade mirror lamp - right terminal A

* E37D dome/reading lamps - overhead console terminal 1

* E37R dome/reading lamps - rear terminal 1

3. Verify the test lamp turns ON and OFF when commanding the Inadvertent Load ON and OFF with a scan tool.

• If the test lamp is always OFF

1. Ignition OFF, disconnect the X7 harness connector at the K9 body control module.

2. Test for infinite resistance between the control circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance

3. Test for less than 2 ohms in the control circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K9 body control module.

• If the test lamp is always ON

1. Ignition OFF, disconnect the X7 harness connector at the K9 body control module, ignition ON.

2. Test for less than 1 V between the control circuit terminal and ground.

• If 1 V or greater, repair the short to voltage on the circuit.

• If less than 1 V, replace the K9 body control module.

• If the test lamp turns ON and OFF

4. Test or replace the appropriate courtesy lamp.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Sunshade Replacement Sunshade Replacement

* Instrument Panel Compartment Lamp Replacement Service and Repair

* Dome and Reading Lamp Replacement Dome and Reading Lamp Replacement

* Control Module References Control Module References for BCM replacement, programming, and setup