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: 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 Signal | 2 | 2 | 2 | -- |
Park Lamp Relay Control | 1 | 1 | B2585 00 | -- |
Park Lamp Control | 1 | 1 | 1 | -- |
Park Lamp Ground | -- | 1 | -- | -- |
Park Lamp Switch Low Reference | -- | 2 | -- | -- |
1. Park Lamps Malfunction 2. Park Lamp Switch Malfunction | ||||
Circuit/System Description
Battery positive 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 turn signal/multifunction switch is supplied with ground at G106 at all times. When the headlamp and panel dimmer 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 FRT PRK LAMP and REAR PRK LAMP fuses to all of the park, tail, license, and marker lamps.
Conditions for Running the DTC
The battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
The park lamp relay control circuit is shorted to voltage.
Action Taken When the DTC Sets
The park lamps will be inoperative from the headlamp and panel dimmer switch.
Conditions for Clearing the DTC
| • | This DTC will clear on current status after the condition for setting the fault is corrected. |
| • | A history DTC will clear after 100 consecutive ignition cycles without a fault present. |
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
Park Lamp Malfunction
- Ignition OFF, disconnect the park lamp relay.
- Connect a test lamp between the relay coil control circuit terminal 86 and B+.
- Ignition ON, command the Park Lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF..
- If all circuits test normal, test or replace the 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, programming, and setup. |
