Buick Regal: Front Fog Lamps 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. Front Fog Lamps Malfunction
2. Front Fog Lamp Switch Malfunction
Circuit/System Description
The front fog lamp relay is supplied with battery voltage at all times. The
front fog lamp switch signal
circuit is grounded momentarily by pressing the front fog lamp switch. The body
control module (BCM)
energizes the front fog lamp relay by applying ground to the front fog lamp
relay control circuit. When
the front fog lamp relay is energized, the relay switch contacts close and
battery voltage is applied
through the front fog lamp fuse to the front fog lamp control circuit which
illuminates the front fog
lamps. With the front fog lamp switch activated the BCM sends a message via
serial data to the
instrument cluster requesting the instrument cluster to illuminate the front fog
indicator.
Reference Information
Schematic Reference
Fog Lights 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 Verification
1. Ignition ON, headlamps ON.
2. Verify the scan tool Front Fog Lamps Switch parameter changes between Active
and Inactive
while commanding the front fog lamps ON and OFF with the front fog lamp switch.
- If the parameter does not change
Refer to Circuit/System Testing - Front Fog Lamp Switch Malfunction.
- Go to next step: If the parameter changes
3. Verify the front fog lamps turn ON and OFF when commanding the Front Fog
Lamps ON and
OFF with a scan tool.
- If the front fog lamps do not turn ON and OFF
Refer to Circuit/System Testing - Front Fog Lamps Malfunction.
- Go to next step: If the front fog lamps turn ON and OFF
4. Verify the front fog lamp indicator on the instrument cluster turns ON and
OFF while
commanding the front fog lamps ON and OFF with the front fog lamp switch.
- If the front fog lamp indicator does not turn ON and OFF
Refer to Circuit/System Testing - Front Fog Lamp Indicator Malfunction.
- Go to next step: If the front fog lamp indicator turns ON and OFF
5. All OK.
Circuit/System Testing
Front Fog Lamp Switch Malfunction
1. Ignition OFF, scan tool disconnected, all doors closed, all accessories
OFF, disconnect the harness
connector at the S30 Headlamp Switch. It may take up to 2 min for all vehicle
systems to power
down.
2. Test for less than 10 Ω between the ground circuit terminal 8 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 10 Ω
3. Ignition ON.
4. Verify the scan tool Front Fog Lamps Relay Command parameter is Inactive.
- Ignition OFF, disconnect the X3 harness connector at the K9 Body Control
Module.
- Test for infinite resistance between the signal circuit terminal 10 and
ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance, replace the K9 Body Control Module.
- Go to next step: If Inactive
5. Install a 3 A fused jumper wire between the signal circuit terminal 10 and
ground.
6. Verify the scan tool Front Fog Lamps Switch parameter is Active.
- Ignition OFF, disconnect the X3 harness connector at the K9 Body Control
Module, ignition
ON.
- Test for less than 1 V between the signal circuit terminal 10 and
ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- Go to next step: If less than 1 V
- Test for less than 2 Ω in the signal 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.
- Go to next step: If Active
7. Test or replace the S30 Headlamp Switch.
Front Fog Lamps Malfunction
1. Ignition OFF, exterior lamps OFF, remove the appropriate E29 Fog Lamp -
Front. It may take up
to 2 min for all vehicle systems to power down.
2. Test for less than 10 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 10 Ω
3. Connect a test lamp between the control circuit terminal 1 and ground,
ignition ON.
4. Verify the test lamp does not turn ON and OFF when commanding the Front Fog
Lamps ON and
OFF with a scan tool.
- If the test lamp turns ON and OFF
Test or replace the E29 Fog Lamp - Front.
- Go to next step: If the test lamp does not turn ON and OFF
5. Ignition OFF, install the E29 Fog Lamp - Front. Disconnect the X2 harness
connector at the X50A
Fuse Block - Underhood, ignition ON.
6. Verify the front fog lamps do not illuminate.
- If the front fog lamps illuminate
- Ignition OFF, remove both E29 Fog Lamp - Front, ignition ON.
- Test for less than 1 V between the control circuit terminal C1 and
ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- Go to next step: If the front fog lamps do not illuminate
7. Ignition OFF, connect a 3 A fused jumper between the control circuit
terminal C1 and B+, ignition
ON.
8. Verify the front fog lamps illuminate.
- If the front fog lamps do not illuminate
- Ignition OFF, remove the 3 A fused jumper wire, remove both E29 Fog Lamp
- Front.
- Test for infinite resistance between the control circuit terminal C1 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, all OK.
- Go to next step: If the front fog lamps illuminate
9. Ignition OFF, connect the X2 harness connector at the X50A Fuse Block -
Underhood.
10. Disconnect the X5 harness connector at the K9 Body Control Module, ignition
ON.
NOTE: The test lamp in the following step will illuminate at LOW
intensity.
This is normal circuit operation and does not indicate a circuit
malfunction.
11. Verify a test lamp illuminates between the control circuit terminal 20
and ground.
- If the test lamp does not illuminate
- Ignition OFF, disconnect the X2 harness connector at the X50A Fuse Block
- Underhood.
- Test for infinite resistance between the control circuit terminal 20 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 X50A Fuse Block - Underhood.
- Go to next step: If the test lamp illuminates
12. Ignition OFF, connect a 3 A fused jumper between the control circuit
terminal 20 and ground,
ignition ON.
13. Verify both E29 Fog Lamp - Front illuminate.
- If the front fog lamps do not illuminate
- Ignition OFF, disconnect the X2 harness connector at the X50A Fuse Block
- Underhood,
ignition ON.
- Test for less than 1 V between the control circuit terminal 20 and
ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the X50A Fuse Block - Underhood.
- Go to next step: If the front fog lamps illuminate
14. Test or replace the K9 Body Control Module.
Front Fog Lamp Indicator Malfunction
1. Ignition ON.
2. Verify the front fog lamp indicator turns ON and OFF when commanding the
Instrument Cluster
All Indicators Test ON and OFF with a scan tool.
- If the front fog lamp indicator is always OFF or remains ON
Replace the P16 Instrument Cluster.
- Go to next step: If the front fog lamp indicator turns ON and OFF
3. Replace the K9 Body Control Module.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Headlamp Switch Replacement
- Front Fog Lamp Replacement
- Engine Wiring Harness Fuse Block Bracket Replacement
- Control Module References for BCM or instrument cluster 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.
Diagnostic
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:
Tire Pressure Indicator Sensor Replacement
Removal Procedure
1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the
Vehicle.
2. Remove the tire and wheel assembly.
3. Dismount the tire from the rim.
4.
NOTE: Never fit the tire pressure indicator sensor on unapproved wheel
r
To adjust the steering wheel:
1. Pull the lever down.
2. Move the steering wheel up
or down.
3. Pull or push the steering wheel
closer or away from you.
4. Pull the lever up to lock the
steering wheel in place.
Do not adjust the steering wheel
while driving.
Steering Wheel Controls
The infotainm