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 Descriptors
DTC B2585 01: Park Lamp Control Circuit Short to VoltageDTC B2585 06: Park Lamp Control Circuit Open or Short to Ground
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Park Lamp Switch ON Signal | 1 | 1 | 1 | -- |
Park Lamp Relay Control | B2585 06 | B2585 06 | B2585 01 | -- |
License Lamp Control | 1 | 1 | 1 | -- |
Park Lamp Control | 1 | 1 | 1 | -- |
License Lamp Ground | -- | 1 | 1 | -- |
Park Lamps - LF Ground | -- | 1 | 1 | -- |
Park Lamps - RF Ground | -- | 1 | 1 | -- |
Tail/Stop and Turn Signal Lamps - LR Ground | -- | 1 | 1 | -- |
Tail/Stop and Turn Signal Lamps - RR Ground | -- | 1 | 1 | -- |
Turn Signal/Multifunction Switch Ground | -- | 1 | 1 | -- |
1. Park, License, and/or Tail Lamps Malfunction | ||||
Circuit/System Description
Battery positive voltage is applied at all times from the PARK LAMPS fuse to both the coil and switched sides of the PARK LAMP Relay in the underhood electrical center. Ground is applied from G201 to the multifunction switch at all times. When the headlamp switch is placed in either the HEAD or PARK position, ground is applied to the park lamp relay control circuit. This energizes the PARK LAMP Relay and applies battery positive voltage to all of the park, tail, license, and marker lamps.
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
B2585 01
This DTC will set when the BCM detects a short to battery voltage in the park lamp relay control circuit.
B2585 06
This DTC will set when the BCM detects an open or short to ground in the park lamp relay control circuit.
Actions Taken When the DTC Sets
| • | When DTC B2585 01 is present, the park lamps will not operate. |
| • | When DTC B2585 06 is present, the park lamps will remain ON. |
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.
- Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal C9 and ground.
- Verify that a test lamp illuminates between the B+ circuit terminal A9 and ground.
- Verify that a test lamp illuminates between the B+ circuit terminal A8 and ground.
- Connect a test lamp between the B+ circuit terminal A9 and the control circuit terminal C8.
- Command the parks lamps ON and OFF with the park lamp switch. 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 illuminates, test the control circuit for a short to voltage. |
| ⇒ | 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 control circuit terminal C9 for a short to ground. If the circuit tests normal, test or replace the park lamp relay. |
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for an open/high resistance. |
| ⇒ | 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 |
