Buick Regal: DTC B2575 or B2699
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 Descriptors
DTC B2575 02
Headlamps Control Circuit Short to Ground
DTC B2699 02
Right Headlamp Control Circuit Short to Ground
Diagnostic Fault Information
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1. Headlamps Malfunction
Circuit/System Description
With the headlamp switch in the ON position, the headlamp switch headlamp ON
signal circuit is
grounded through the headlamp switch. The body control module (BCM) responds by
applying battery
positive voltage to the left and right low beam headlamp control circuits
illuminating the low beam
headlamps.
Conditions for Running the DTC
- Battery voltage must be between 9-16 V.
- Low beam headlamps ON.
Conditions for Setting the DTC
DTC B2575 02
The BCM detects a short to ground in the left low beam headlamp control
circuit.
DTC B2699 02
The BCM detects a short to ground in the right low beam headlamp control
circuit.
Actions Taken When the DTC Sets
- When DTC B2575 sets, the left low beam headlamp will be inoperative.
- When DTC B2699 sets, the right low beam headlamp 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
Headlights/Daytime Running Lights (DRL) Wiring Schematics
Connector End View Reference
COMPONENT CONNECTOR END VIEWS - INDEX
Description and Operation
Exterior 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
DTC B2575
1. Ignition OFF, exterior lamps OFF, remove the E4G Headlamp - Left Low Beam.
It may take up to
2 min for all vehicle systems to power down.
2. Test for less than 5 Ω between the ground circuit at the socket terminal 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 at the socket terminal and
ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Left Headlamp Low
Beam ON and
OFF with a scan tool.
- If the test lamp is always OFF
- Ignition OFF, disconnect the X4 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 X4 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 E4G Headlamp - Left Low Beam.
DTC B2699
1. Ignition OFF, exterior lamps OFF, remove the E4H Headlamp - Right Low
Beam. It may take up
to 2 min for all vehicle systems to power down.
2. Test for less than 5 Ω between the ground circuit at the socket terminal 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 at the socket terminal and
ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Right Headlamp Low
Beam ON
and OFF with a scan tool.
- If the test lamp is always OFF
- Ignition OFF, disconnect the X4 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 X4 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 E4H Headlamp - Right Low Beam.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Headlamp Bulb Replacement - Left Side (High Beam) Headlamp Bulb
Replacement - Left
Side (Low Beam)
- Headlamp Bulb Replacement - Right Side (High Beam) Headlamp Bulb
Replacement -
Right Side (Low Beam)
- 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:
DISC BRAKE SYSTEM DESCRIPTION AND OPERATION
System Component Description
The measurement used to identify the brake system indicates the minimum wheel
size that must be
installed. For example: If a 16 inch brake system is identified, the smallest
wheel that can be installed is a
16 inch wheel.
Th
SPECIAL TOOLS
DT-26941
J-26941
Remover
DT-37228
J-37228
Seal Cutter
DT-43911
J-43911
Selector Shaft Seal
Remover
DT-44215
J-44215
Rear Seal Installer
DT-44809
J-44809
Output Shaft Seal
Installer
DT-45124
J-45124
Removal Bridge
DT-45124-9
J-45124-9
Puller Leg
DT-47865
Bearing Remover
DT-48056