For 1990-2009 cars

### 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 B2530 02: Front Fog Lamps Control Circuit Short to Ground
DTC B2530 05: Front Fog Lamps Control Circuit Short to Battery or Open

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Fog Lamp Switch Signal | 2 | 2 | 2 | --
Fog Lamp Relay Control | B2530 02 | B2530 05 | B2530 05 | --
Fog Lamp Control | 1 | 1 | 1 | --
Fog Lamp - LF Ground | -- | 1 | -- | --
Fog Lamp - RF Ground | -- | 1 | -- | --
Fog Lamp Relay Ground | -- | 1 | -- | --
Fog Lamp Switch Ground | -- | 2 | -- | --
1. Fog Lamps Malfunction 2. Fog Lamp Switch Malfunction

### Circuit/System Description

The fog lamp relay is supplied with battery voltage at all times. The fog lamp switch signal circuit is grounded momentarily by pressing the fog lamp switch. The body control module (BCM) energizes the fog lamp relay by applying voltage to the fog lamp relay control circuit. When the fog lamp relay is energized, the relay switch contacts close and battery voltage is applied through the FOG LAMP fuse to the fog lamp control circuit which illuminates the fog lamps.

### Conditions for Running the DTC

• | Battery voltage must be between 9-16 volts.

• | Fog lamps ON.

### Conditions for Setting the DTC

#### DTC B2530 02

The DTC will set when the BCM detects a short to ground in the fog lamp relay control circuit for 5 seconds or greater.

#### DTC B2530 05

The DTC will set when the BCM detects a short to voltage or an open in the fog lamp relay control circuit for 5 seconds or greater.

### Actions Taken When the DTC Sets

#### DTC B2530 02

When the DTC is present, the fog lamps will not operate when the park lamps are ON and the fog lamp switch is active.

#### DTC B2530 05

When the DTC is present, for a short to voltage condition the fog lamps and the fog lamp switch indicator will be on at all times when the park lamps are OFF and the fog lamp switch is inactive. For an open condition, the fog lamps and the fog lamp switch indicator will not operate when the park lamps are ON and the 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 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 Testing

1. Ignition OFF, disconnect the X3 harness connector at the underhood fuse block.
2. Ignition OFF, exterior lamps OFF, test for less than 5 ohms between the ground circuit terminal F2 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition OFF, connect the X3 harness connector at the underhood fuse block.
4. Disconnect the X2 harness connector at the underhood fuse block.
5. Connect a test lamp between the control circuit terminal C3 and ground.
6. Command the Fog Lamps ON and OFF with a scan tool. 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 voltage. If the circuit tests normal, replace the BCM.

⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

7. If all circuits test normal, replace the underhood fuse block.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Underhood Electrical Center or Junction Block Bracket Replacement

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