B1480
DTC B1480
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptor
DTC B1480 00
- Battery Rundown Protection
Diagnostic Fault Information
Circuit/System Description
Battery voltage is supplied at all times to the body control module (BCM) from the 10A INT LAMPS fuse located in the rear fuse block. The BCM then applies this voltage to the following lamps:
-V4U Base Vehicle
* Instrument panel (I/P) compartment lamp
* Courtesy lamp module
* Rear compartment lamp
* Vanity mirror lamps
+V4U Limousine
* I/P compartment lamp
* Rear compartment lamp
* Vanity mirror lamps
+V4U/B9Q Hearse
* I/P compartment lamp
* Overhead console lamps
* Overhead lamp relay
* Rear compartment lamp
* Rear roof rail lamps
* Vanity mirror lamps
In the event that any of these lamps were to remain illuminated for more the 20 minutes with the ignition switch in the OFF position, the BCM will deactivate the inadvertent power courtesy lamps circuit to prevent total battery discharge.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The BCM detects a short to ground on the inadvertent power courtesy lamp circuit.
Action Taken When the DTC Sets
The BCM will deactivate inadvertent power to the courtesy lamps.
Conditions for Clearing the DTC
* The conditions for setting the DTC are no longer present.
* A history DTC clears after 100 malfunction-free ignition cycles.
Reference Information
Schematic Reference
Interior Lights Schematics (Interior Lights Schematics)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Interior Lighting Systems Description and Operation (Interior Lighting Systems Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for Scan Tool Information
Circuit/System Verification
Ignition ON, activate each inadvertent power courtesy lamp. Ignition OFF, activate each inadvertent power courtesy lamp. Lamps should remain illuminated for more the 20 minutes with the ignition switch in the OFF position. The BCM will deactivate the inadvertent power courtesy lamps circuit to prevent total battery discharge.
Circuit/System Testing
1. Ignition OFF, disconnect the appropriate harness connector at each component fed by the inadvertent power courtesy lamp circuit.
2. Ignition ON, with a scan tool clear the DTC.
3. Operate the vehicle within the Conditions for Running the DTC and verify the DTC does not reset.
• If the DTC resets, test the inadvertent power courtesy lamp circuit for a short to ground. If the circuit test normal, replace the BCM.
4. Connect each component one at a time and verify that the DTC does not reset as current.
• If the DTC resets, test or replace the component responsible for setting the DTC.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Instrument Panel Compartment Lamp Switch Replacement (Service and Repair)
* Instrument Panel Storage Compartment Lamp Replacement (Service and Repair)
* Roof Rail Rear Courtesy Lamp Switch Replacement (Roof Rail Rear Courtesy Lamp Switch Replacement)
* Roof Rail Rear Courtesy Lamp Replacement (Roof Rail Rear Courtesy Lamp Replacement)
* Rear Compartment Courtesy Lamp Replacement (Rear Compartment Courtesy Lamp Replacement)
* Relay Replacement (Attached to Wire Harness) (Relay Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (Relay Replacement (Within an Electrical Center))
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming