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 |
|---|---|---|---|---|
Parklamp Relay B+ | 1 | 1 | -- | -- |
Parklamp Switch Signal | 2 | 2 | 2 | -- |
Parklamp Control | 1 | 1 | 1 | -- |
Parklamp Relay Control | 1 | 1 | 1 | -- |
Parklamp Ground | -- | 1 | -- | -- |
Headlamp Switch Ground | -- | 2 | -- | -- |
1. Parklamp Malfunction 2. Parklamp Switch Malfuntion | ||||
Circuit/System Description
The park, tail, marker, license, are turned on when the headlamp switch is placed in the PARK or ON position or anytime the headlights are requested. The I/P BATT fuse in the engine wiring harness junction block supplies battery positive voltage to both the parklamp relay switch contacts and the parklamp coil circuit. The body control module (BCM) provides a ground or control circuit to the parklamp relay coil circuit. When the parklamps are turned on, the BCM energizes the parklamp relay. Current flow is from the parklamp relay to the individual parklamp circuit fuses and to their respective park, tail, marker, and license lamps. The front park and marker lamps are grounded at G107 and G103. The tail lamps are grounded at G401 and G402. The license lamps are grounded at G401. If the driver places the headlight switch in the ON position after the ignition switch has been turned OFF, the park, tail, marker, license, will remain on until turned off or the battery runs dead.
Conditions for Running the DTC
The battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
| • | When the BCM receives a parklamp request the parklamp relay control circuit is shorted to voltage. |
| • | When the BCM is not receiving a parklamp request the parklamp relay control circuit is open or shorted to ground. |
Action Taken When the DTC Sets
The parklamps will be inoperative or always on.
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
- Ignition OFF, disconnect the parklamp relay.
- Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 85 and ground.
- Connect a test lamp between the relay control circuit terminal 86 and the B+ termainal 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, replace the parklamp relay.
| ⇒ | If the test lamp does not illuminate, test the circuit for a short to ground or 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, programming, and setup.
