B2585

DTC B2585

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B2585
- Park Lamp Circuit

Diagnostic Fault Information






Circuit/System Description

Battery positive voltage is supplied to the PRK LAMP relay at all times. The BCM grounds the park lamp relay control circuit in order to activate the relay. With the park lamp relay activated, voltage is supplied to the park lamp supply voltage circuit illuminating the park lamps, license lamps, and marker lamps.

Conditions for Running the DTC

* The ignition switch is in the RUN position.
* The ambient light sensor senses a dark condition, automatic lamp control (ALC) park lamps ON, or the headlamp switch is in the park or head ON position.

Conditions for Setting the DTC

The park lamp supply voltage circuit is shorted to voltage.

Action Taken When the DTC Sets

The park lamps are always on or inoperative.

Conditions for Clearing the DTC

100 consecutive ignition cycles have been recorded without the DTC being detected.

Circuit/System Verification

Ignition ON, command the park lamps ON and OFF with a scan tool, observe the operation of park lamps. The park lamps should turn ON and OFF with each command.

Circuit/System Testing

1. Ignition OFF, disconnect the PRK LAMP relay.
2. Ignition ON, verify that a test lamp does not illuminate between the relay coil control circuit terminal 86 and ground.

^ If the test lamp illuminates, test the control circuit for a short to voltage.

3. If all circuits test normal, test or replace the BCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Relay Replacement (Attached to Wire Harness) Relay Replacement (Within an Electrical Center)