B2585

DTC B2585

Diagnostic Instructions

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



DTC Descriptors
DTC B2585 00
- Left Parklamp Control Circuit




Diagnostic Fault Information






Circuit/System Description

All Countries Except Japan, Korea, Taiwan

Voltage is applied at all times to the PRK LAMP relay from battery voltage. When the headlamp switch is placed in the PARK position, ground is applied through the park lamp switch ON signal circuit to the body control module (BCM) . The BCM then applies a ground to the park lamp relay control circuit. This energizes the relay and applies voltage through both PRK LAMP fuses and the park lamp supply voltage circuits illuminating the park, tail, and license lamps.

Japan, Korea, Taiwan Only

Voltage is applied at all times to the PRK LAMP relay and the RT PRK LAMP relay from battery voltage. When the headlamp switch is placed in the PARK position, ground is applied through the park lamp switch signal circuit to the BCM. The BCM then applies a ground to both the park lamp relay control circuits. This energizes the relays and applies voltage through both PRK LAMP fuses and the park lamp supply voltage circuits illuminating the park, tail, and license lamps.


Conditions for Running the DTC

The ignition is ON. The park lamps must be commanded ON by the headlamp switch.


Conditions for Setting the DTC

The BCM detects a short to voltage on the park lamp relay control circuit while trying to apply a ground to energize the relay.


Action Taken When the DTC Sets

The BCM turns off the park lamp relay control for the remainder of the ignition cycle.


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.



Reference Information
Schematic Reference

Exterior Lights Schematics (Exterior Lights Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Exterior Lighting Systems Description and Operation (Exterior Lighting Systems Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Programming and Relearning (Programming and Relearning) for Scan Tool Information


Circuit/System Verification

Ignition ON, turn the headlamp switch to the park lamps ON position. Observe the scan tool Park Lamp Relay Command parameter. The reading should display On and the park lamps should illuminate.


Circuit/System Testing

Caution: The high intensity discharge system produces high voltage and current. To reduce the risk of severe shocks and burns:

* Never open the high intensity discharge system ballast or the arc tube assembly starter.
* Never probe between the high intensity discharge system ballast output connector and the arc tube assembly.



1. Ignition OFF, remove the appropriate PRK LAMP Relay or RT PRK LAMP relay from the rear fuse block.
2. Connect a test lamp between B+ and the appropriate relay control circuit terminal listed below.

* PRK LAMP relay terminal 101
* RT PRK LAMP relay terminal 92 - Japan, Korea, Taiwan only

3. Ignition ON, command the Parking 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 ground. If the circuit tests normal, replace the 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 BCM.

4. If the circuit tests normal, test or replace the park lamp relay.



Component Test


Relay Test
1. Ignition OFF, disconnect the park lamp relay.
2. Test for 70-100 ohms of resistance between terminals 85 and 86.

• If the resistance is not within the specified range, replace the relay.

3. Test for infinite resistance between the following terminals:

* 30 and 85
* 30 and 86
* 30 and 87
* 85 and 87


• If not the specified value, replace the relay.

4. Install a 10A fused jumper wire between relay terminal 85 and B+. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms of resistance between terminals 30 and 87.

• If greater than the specified range, replace the relay.




Repair Instructions

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

* Relay Replacement (Attached to Wire Harness) (Relay Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (Relay Replacement (Within an Electrical Center))
* Programming and Relearning (Programming and Relearning) for BCM replacement, setup, and programming