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 diangostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC B2585 00: Park Lamp Control Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Park Lamp Relay Control | B2585 00 | B2585 00 | B2585 00 | --

### Circuit/System Description

Voltage is applied at all times to the park lamp relay from battery voltage. When the headlamp switch is placed in the PARK position, ground is applied through the headlamp switch park lamp signal circuit to the body control module (BCM) . The BCM then applies a ground to the park lamp relay control circuit. This engages the relay and applies voltage through the park lamp fuses and to all the park lamps.

### Conditions for Running the DTC

The ignition is ON. The park lamps must be commanded ON by the headlamp switch or by the BCM in low light conditions in AUTO mode.

### Conditions for Setting the DTC

The BCM detects a short to ground, open, high resistance, or short to voltage on the park lamp relay control circuit.

### Action Taken When the DTC Sets

All park lamps are inoperative.

### Conditions for Clearing the DTC

• | The conditions for setting the DTC are no longer present.

• | A history DTC clears after 100 malfunction-free ignition cycles.

• | The BCM receives the clear code command from the scan tool.

### Reference Information

#### Schematic Reference

Exterior Lights Schematics

#### Connector End View Reference

Lighting Systems Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

• | Scan Tool Output Controls

• | Scan Tool Data List

• | Scan Tool Data Definitions

### Circuit/System Verification

Ignition ON, activate the Parking Lamp output control on the scan tool. The Park Lamp Relay Command parameter in the data list should display On and the park lamps should illuminate.

### Circuit/System Testing

1. Ignition OFF, disconnect the underhood fuse block connector C5 and test for a short to voltage, short to ground, an open, or high resistance at the connector terminal C8.
2. With a scan tool, activate the Parking Lamp output control on the scan tool and test for a ground at the underhood fuse block connector C5 terminal C8.

⇒ | If a ground signal is present, replace the underhood fuse block. If a ground signal is not present, replace the BCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

For BCM replacement, setup, and programming refer to Control Module References .