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 Signal | 2 | 2 | 2 | -- |
Park Lamp Control | 1 | 1 | 1 | -- |
Park Lamp Relay Control Circuit | 1 | 1 | B2585 00 | -- |
Headlamp and Panel DImmer Switch Ground | -- | 2 | -- | -- |
Park Lamps Ground | -- | 1 | -- | -- |
| ||||
Circuit/System Description
The park, tail and marker lamps, including the license lamps, are turned ON when the headlamp switch is placed in the PARK or HEAD position or anytime the headlights are requested. The underhood fuse block supplies battery positive voltage to both the park lamp relay switch contacts and the park lamp coil circuit. The BCM provides a ground or control circuit to the park lamp relay coil circuit. When the park lamps are turned ON, the BCM energizes the park lamp relay. If the headlight switch is left in the ON position, the inadvertent power control feature will turn OFF the park, tail and marker lamps approximately 10 minutes after the ignition switch is turned to the OFF position. If the driver places the headlight switch in the ON position after the ignition switch has been turned OFF, or if the ignition switch is in the ACCY position, the park, tail and marker lamps will remain ON until turned OFF or the battery runs dead.
Conditions for Running the DTC
| • | The Ignition is ON. |
| • | The park lamps must be commanded ON by the BCM. |
Conditions for Setting the DTC
DTC B2585 00 BCM sets when the BCM detects a short to voltage on the park lamp relay control circuit.
Action Taken When the DTC Sets
All park, license, and tail lamps are inoperative.
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. |
| • | The BCM receives the clear code command from the scan tool. |
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 PRK LAMP relay.
- Connect a test lamp between the relay control circuit terminal 86 and the B+ circuit terminal 85.
- 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 all circuits test normal, test or replace the PRK LAMP relay.
| ⇒ | If the test lamp is always ON, test the relay control circuit for a short to ground. If the circuit tests normal, replace the BCM. |
| ⇒ | If the test lamp is always OFF, test the relay 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 |
