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 Descriptor
DTC B2585 00: Park Lamp Control CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Park Lamp Relay B+ | 1 | 1 | -- | -- |
Park Lamp Switch ON Signal | 1 | B257A 00 | 1 | -- |
Park Lamp Relay Control | 1 | 1 | B2585 00 | -- |
License Lamp Control | 1 | 1 | 1 | -- |
Park Lamp Control | 1 | 1 | 1 | -- |
License Lamp Ground | -- | 1 | -- | -- |
Park Lamps - LF Ground | -- | 1 | -- | -- |
Park Lamps - RF Ground | -- | 1 | -- | -- |
Side Marker Lamp - Left Rear Ground | -- | 1 | -- | -- |
Side Marker Lamp - Right Rear Ground | -- | 1 | -- | -- |
Tail/Stop Lamp - Left Ground | -- | 1 | -- | -- |
Tail/Stop Lamp - Right Ground | -- | 1 | -- | -- |
Headlamp And Panel Dimmer Switch Ground | -- | 1 | -- | -- |
1. Park, License, and/or Tail Lamps Malfunction | ||||
Circuit/System Description
Battery voltage is applied at all times to both the coil and switch sides of the PRK LAMP relay located in the underhood fuse block. The headlamp and panel dimmer switch is suppled with ground at G201 at all times. When the headlamp switch is placed in either the HEAD or PARK position, ground is applied to the park lamp signal circuit to the body control module (BCM). The BCM responds by applying ground to the park lamp relay control circuit. This energizes the park lamp relay coil causing the relay switch contacts to close allowing battery voltage to flow through the LT PRK and RT PRK fuses to all of the park, tail, license, and marker lamps.
Conditions for Running the DTC
| • | Battery voltage must be between 9-16 volts. |
| • | Park lamps ON. |
Conditions for Setting the DTC
DTC B2585 00 will set when the BCM detects a short to voltage in the park lamp relay control circuit.
Actions Taken When the DTC Sets
When DTC B2585 00 is present, the park lamps will not operate.
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
Connector End View Reference
Description and Operation
Exterior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the park lamp relay.
- Connect a test lamp between the control circuit terminal 85 and the B+ circuit terminal 86.
- Command the Parking Light Test ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
- If all circuits test normal, test or replace the park lamp relay.
| ⇒ | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
