B2585

DTC B2585

DTC Descriptor
DTC B2585 00
- Park Lamp Control Circuit - Domestic

DTC B2585 00
- Left Park Lamp Control Circuit - Export

Diagnostic Fault Information

Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview






Circuit/System Description

Domestic

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 park lamp switch 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.

Export

Voltage is applied at all times to the left park 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 the left park lamp relay control circuit. This engages the relay and applies voltage through the park lamp fuses and to all the left park 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 the circuit.

Action Taken When the DTC Sets

Domestic

All park lamps are inoperative.

Export

The left side park lamps are all inoperative.

Conditions for Clearing the DTC

The BCM clears this code from current when the fault is removed from the system.

Circuit/System Verification

Ignition ON, turn the park lamps ON. The park lamps should illuminate.

Circuit/System Testing

1. Ignition ON, automatic head lights OFF, verify the scan tool Park lamp Switch parameter displays active with the park lamp switch in the ON position.

• If the scan tool displays inactive, test the head lamp switch park lamps signal circuit and head lamp switch ground circuit for a short to voltage or an open/high resistance. If the circuits test normal, replace the head light switch.

2. Ignition OFF, disconnect the park lamp relay.
3. Verify that a test lamp illuminates between the B+ circuit on the coil side and switch side of the relay terminals when connected to ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the left and right park lamp supply voltage circuits for a short to ground. If the circuits test normal replace the park lamp relay.

4. Disconnect the harness connector at a park lamp that is inoperative.
5. Test for less than 1.0 ohm of resistance between the inoperative lamp ground circuit terminal and ground

• If greater than 1.0 ohm, test the ground circuit for an open/high resistance.

6. Connect the harness connector at the lamp.
7. Connect a 30-amp fused jumper wire between the B+ circuit terminal and the park lamp supply voltage circuit terminal. Verify the park lamps illuminate.

• If the park lamps do not illuminate, test the left and right park lamp supply voltage circuit for an open/high resistance. If the circuits test normal, replace the inoperative park lamp.

8. Connect a test lamp between the B+ circuit terminal on the coil side of the relay and the park lamp relay control circuit terminal.
9. Command the park lamp relay 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 OFF, test the park lamp relay control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the Body Control Module.

10. If all circuits test normal, replace the park lamp relay.

Repair Instructions

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

* Relay Replacement (Attached to Wire Harness) Relay Replacement (Within an Electrical Center)
* Programming and Relearning for BCM setup, and programming. Programming and Relearning
* Headlamp Switch Replacement Verification Tests