For 1990-2009 cars

### Diagnostic Instructions

1. Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
2. Review Strategy Based Diagnosis for an overview of the diagnostic approach.
3. Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC B2530 01: Front Fog Lamps Control Circuit Short to Battery
DTC B2530 02: Front Fog Lamps Control Circuit Short to Ground
DTC B2530 04: Front Fog Lamps Control Circuit Open

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Front Fog Lamps Control | B2530 02 | B2530 04 | B2530 01 | --

### 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 supply voltage circuit which illuminates the front fog lamps.

### Conditions for Running the DTC

Front fog lamps activated

### Conditions for Setting the DTC

#### B2530 01

The BCM detects a short to voltage on the control circuit.

#### B2530 02

The BCM detects a short to ground on the control circuit.

#### B2530 04

The BCM detects an open control circuit.

### Conditions for Clearing the DTC

The condition for setting the DTC is no longer present.

### Reference Information

#### Schematic Reference

Fog Lights Schematics

#### Connector End View Reference

Component Connector End Views

#### 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

Ignition ON, perform the Front Fog Lamps Relay Command test. The front fog lamps should be ON / OFF

### Circuit/System Testing

1. Ignition OFF, disconnect the KR46 Front Fog Lamp Relay.
2. Connect a test lamp between the B+ circuit terminal 85 and the control circuit terminal 86.
3. Ignition ON, perform the Front Fog Lamps Relay Command test. The test lamp should turn ON and OFF when changing between the commanded states.

⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K9 Body Control Module (BCM).

⇒ | If the test lamp is always OFF, test the control circuit for a short to voltage or an open / high resistance. If the circuit tests normal, replace the K9 Body Control Module (BCM).

4. If all circuits test normal, replace the KR46 Front Fog Lamp Relay.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Relay Replacement

• | Control Module References for BCM replacement, setup and programming