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 reading lamps, left and right sunshade lamps, and instrument panel compartment lamp via the courtesy lamp control circuit. When the instrument panel compartment or a sunshade mirror is opened, the switch contact close allowing battery voltage to flow illuminating the respective lamps. The front 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 courtesy lamps controlled by the circuit.

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 Front

Description and Operation

Exterior Lighting Systems Description and Operation Exterior Lighting Systems

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

Note: Each courtesy lamp component controlled by the courtesy lamp control circuit terminal 2 X7 may need to be disconnected to isolate a short to voltage or a short to ground. Use the schematic to identify the following:

* Each component's control and ground circuit terminals

* Courtesy lamp components the vehicle is equipped with

* Component locations on the courtesy lamp control circuit

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

* A3L sunshade - left

* A3R sunshade - right

* E28 center console compartment lamp - with LS/LSE

* E37M dome/reading lamps - middle

* E37EL dome/reading lamps - front overhead console left

* E37ER dome/reading lamps - front overhead console right

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

* A3L sunshade - left terminal A

* A3R sunshade - right terminal A

* E28 center console compartment lamp - with LS/LSE terminal 1

* E37M dome/reading lamps - middle terminal 1

* E37EL dome/reading lamps - front overhead console left terminal A

* E37ER dome/reading lamps - front overhead console right terminal A

3. Place both dome/reading lamps - front overhead console switches in the ON position.

4. 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

5. Test or replace the appropriate courtesy lamp.

Repair Instructions

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

* Dome and Reading Lamp Switch Replacement Dome and Reading Lamp Switch Replacement

* Dome Lamp Bulb Replacement Service and Repair

* Sunshade Illuminated Mirror Lamp Bulb Replacement Sunshade Illuminated Mirror Lamp Bulb Replacement

* Front Floor Console Armrest Compartment Lamp Replacement Front Floor Console Armrest Compartment Lamp Replacement

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