Buick Regal: Rear Compartment Lamp Malfunction
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.
Diagnostic Fault Information
1. Rear Compartment Lamp Malfunction
2. Trunk Release Malfunction
Circuit/System Description
The body control module (BCM) applies battery voltage to the rear compartment
courtesy lamp through
the rear compartment lamp control circuit. When the BCM receives a rear
compartment lid open input
from the rear compartment lid latch, the BCM applies battery voltage to the rear
compartment lamp
control circuit illuminating the rear compartment courtesy lamp. In the event
that the rear compartment
lamp 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 rear compartment lamp control
circuit to prevent total
battery discharge.
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 Verification
Without TC2
1. Ignition ON.
2. Verify the scan tool Liftgate Rear Close Switch parameter changes between
Inactive to Active
when pressing the B70 Liftgate Close Switch.
- If the parameter does not change
Refer to Circuit/System Testing
- Go to next step: If the parameter does change
Go to next step: Refer to Circuit/System Testing
With TC2
1. Ignition - On / Vehicle - In Service Mode
2. Operate the component:Liftgate - Closed
Verify the scan tool parameter:Rear Closure Ajar Switch=Inactive
- If not the specified state
Refer to: Circuit/System Testing Rear Hatch/Gate Ajar Indicator
Malfunction (With TB5)
Rear Hatch/Gate Ajar Indicator Malfunction (Without TB5)
- Go to next step: If the specified state
3. Operate the component:Liftgate - Ajar
Verify the scan tool parameter:Rear Closure Ajar Switch=Active
- If not the specified state
Refer to: Circuit/System Testing Rear Hatch/Gate Ajar Indicator
Malfunction (With TB5)
Rear Hatch/Gate Ajar Indicator Malfunction (Without TB5)
- Go to next step: If the specified state
Go to next step: Refer to: Circuit/System Testing
Circuit/System Testing
1. Ignition OFF, exterior lamps OFF, trunk latch latched, disconnect the
harness connector at the E8S
rear compartment courtesy lamp.
2. Test for less than 5 Ω between the ground circuit terminal 2 and ground.
- Ignition OFF.
- Test for less than 2 Ω in the ground circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, repair the open/high resistance in the ground
connection.
- Go to next step: If less than 5 Ω
3. Connect a test lamp between the control circuit terminal 1 and ground,
ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Trunk Lamp 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
5. Test or replace the E8S rear compartment courtesy lamp.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Rear Compartment Courtesy Lamp Replacement (5-Door Hatchback 68) Rear
- Compartment Courtesy Lamp Replacement (5-Door Wagon 35)
- 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:
The speedometer shows the
vehicle's speed in either kilometers
per hour (km/h) or miles per
hour (mph).
Odometer
The odometer shows how far the
vehicle has been driven, in either
kilometers or miles.
Tachometer
The tachometer displays the engine
speed in revolutions per
minute (rpm).
For vehicles w
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.
Refer to Diagnostic Procedure Instructions for an overview of each
diagnostic category.
DTC Descripto