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, 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 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 reading lamp control circuit.
Actions Taken When the DTC Sets
The BCM will disable the circuit and the reading lamp 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
* Body Control System Schematics [1][2]Body Control Systems
Connector End View Reference
Component Connector End Views Outside Rearview Mirror - Driver
Description and Operation
Interior Lighting Systems Description and Operation Interior 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
1. Ignition OFF, exterior lamps OFF, disconnect the harness connectors at the components listed below.
* E37F dome/reading lamps - front
* E37R dome/reading lamps - rear
* E31L sunshade mirror lamp - left
* E31R sunshade mirror lamp - right
* E27 instrument panel compartment lamp
2. Connect a test lamp between the appropriate control circuit terminal listed below and ground.
* E37F dome/reading lamps - front terminal 1
* E37R dome/reading lamps - rear terminal 1
* E31L sunshade mirror lamp - left terminal A
* E31R sunshade mirror lamp - right terminal A
* E27 instrument panel compartment lamp 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 Instrument Panel Compartment Lamp Replacement
* Dome Lamp Bulb Replacement Service and Repair
* Reading Lamp Replacement Service and Repair
* Control Module References Control Module References for BCM replacement, programming, and setup