Buick Regal: DTC B2530

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 B2530 02

Front Fog Lamps Control Circuit Short to Ground

Diagnostic Fault Information

1. Front Fog Lamps 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 to the front fog lamp control circuit which illuminates the front fog lamps.

Conditions for Running the DTC

• Battery voltage must be between 9-16 V.
• Front fog lamps ON.

Conditions for Setting the DTC

The BCM detects a short to ground in the front fog lamp relay control circuit.

Actions Taken When the DTC Sets

The front fog lamps will not operate when the park lamps are ON and the front fog lamp switch is active.

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

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 Testing

1. Ignition OFF, 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.

2. Verify a test lamp illuminates between the control circuit terminal 20 and ground.

• If the test lamp does not illuminate

1. Ignition OFF, disconnect the X2 harness connector at the X50A Fuse Block - Underhood.
2. 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
3. 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

3. Ignition OFF, connect a 3 A fused jumper between the control circuit terminal 20 and ground.

4. Remove the F7UA fog lamp fuse at the X50A Fuse Block - Underhood, ignition ON.

5. Verify a test lamp illuminates between the F7UA fog lamp fuse B+ switch control terminal and ground.

• If the test lamp does not illuminate

1. Ignition OFF, disconnect the X2 harness connector at the X50A Fuse Block - Underhood, ignition ON.
2. 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 test lamp illuminates

6. Test or replace the K9 Body Control Module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Engine Wiring Harness Fuse Block Bracket Replacement
• Control Module References for BCM replacement, programming, and setup

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