Buick Regal: DTC B1480
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- 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 02
Battery Rundown Protection Circuit Short to Ground
Diagnostic Fault Information
1. Courtesy Lamps Malfunction
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, center
console armrest, 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 occupants when additional cabin lighting is required. In the
event that any of these
courtesy lamps were to remain illuminated for more than 10 min with the ignition
switch in the OFF
position, 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
terminal 3 X7.
Actions Taken When the DTC Sets
- The BCM will disable the control circuit and all lamps controlled by the
courtesy lamps control
circuit terminal 3 X7 will be inoperative.
- Dome lamps 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 Wiring Schematics
Connector End View Reference
COMPONENT CONNECTOR END VIEWS - INDEX
Description and Operation
Interior Lighting Systems Description and Operation
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connectors at the components listed
below.
- A3L Sunshade - Left
- A3R Sunshade - Right
- A98 Front Overhead Console Assembly
- E27 Instrument Panel Compartment Lamp
- E37J Dome/Reading Lamps - Left Roof Rail (C3U)
- E37H Dome/Reading Lamps - Right Roof Rail (C3U)
- E37R Dome/Reading Lamps - Rear (C93-C3U)
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
- A98 Front Overhead Console Assembly terminal 7
- E27 Instrument Panel Compartment Lamp terminal 1
- E37J Dome/Reading Lamps - Left Roof Rail terminal 1 (C3U)
- E37H Dome/Reading Lamps - Right Roof Rail terminal 1 (C3U)
- E37R Dome/Reading Lamps - Rear terminal 4 (C93-C3U)
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
- Ignition OFF, disconnect the X7 harness connector at the K9 Body Control
Module.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- Go to next step: If infinite resistance
- Test for less than 2 Ω in the control circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K9 Body Control Module.
- If the test lamp is always ON
- Ignition OFF, disconnect the X7 harness connector at the K9 Body Control
Module, ignition
ON.
- 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.
- Go to next step: If the test lamp turns ON and OFF
4. Test or replace the courtesy lamp.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Center Reading Lamp Replacement (without Sunroof)
- Instrument Panel Compartment Lamp Replacement
- Rear Seat Position Center Reading Lamp Replacement (with Sunroof)
- Roof Console Replacement
- Sunshade Replacement
- Control Module References for BCM replacement, programming, and setup
READ NEXT:
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
SEE MORE:
Special Tools
CH-804 Drive Axle Boot Clamp Pliers
Equivalent regional tools:Special Tools
Removal Procedure
1.
Intermediate Steering Shaft Inner Boot(1) - Remove.
2. Remove the front tire and wheel assembly.
3.
Cut the intermediate steering shaft outer boot clamp (1).
DISCARD the clamp.
4.
Removal Procedure
WARNING: Brake Fluid Irritant Warning.
WARNING: Use of eye goggles is necessary to prevent personal injury.
CAUTION: Brake Fluid Effects on Paint and Electrical Components Caution.
1. Remove the front tire and wheel assembly.
2.
Front Brake Pipe Fitting(1)@Front Brake Hose(3) - Re