For 1990-2009 cars only
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 CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Parklamp Relay Control Circuit | B 2585 00 | B 2585 00 | -- | -- |
Parklamp Relay Supply Voltage | 1 | 1 | -- | -- |
Parklamp Switch Signal Circuit | 1 | 1 | -- | -- |
Body Control Circuit | 1 | 1 | -- | -- |
1. Parklamps Inoperative | ||||
Circuit/System Description
The body control module (BCM) turns ON the park lamp relay when the ambient light sensor senses a dark condition. Battery positive voltage is supplied to the park lamp relay at all times through the PARK Left or PARK Right fuse. The BCM grounds the park lamp relay control circuit in order to activate the relay. With the park lamp relay activated voltage is supplied to the park lamp supply voltage circuit illuminating the park lamps, license lamps, marker lamps, and signaling the BCM.
Conditions for Running the DTC
| • | The ignition switch is in the RUN position. |
| • | The ambient light sensor senses a dark condition, automatic lamp control (ALC) park lamps ON, or the headlamp switch is in the park or head ON position. |
Conditions for Setting the DTC
| • | The park lamp relay control circuit in open. |
| • | The park lamp supply voltage circuit is open between the instrument panel Underhood fuse block and the BCM for 5 seconds. |
| • | The park lamp supply voltage circuit is shorted to ground. |
| • | The park lamp relay is stuck in the OPEN position. |
Action Taken When the DTC Sets
| • | The park lamps will operate properly if the park lamp supply voltage circuit is open between the Underhood fuse block and the BCM. |
| • | The park lamps will not illuminate if the relay is stuck open or the LT PRK or RT PRK fuse in the Underhood fuse block is open. |
Conditions for Clearing the DTC
| • | 100 consecutive ignition cycles have been recorded without the DTC being detected. |
| • | Using a scan tool can clear the DTC. |
Diagnostic Aids
| • | The BCM controls voltage to the park lamps. |
| • | The BCM monitors the parklamp switch signal circuit for power to engage the park lamps. |
Reference Information
Schematic Reference
Connector End View Reference
Lighting Systems Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
Ignition ON, command the park lamps ON and OFF with a scan tool, observe the operation of park lamps. The park lamps should turn ON and OFF with each command.
Circuit/System Testing
- Ignition OFF, disconnect the parklamp relay.
- Ignition ON, verify the parklamp is deactivated.
- Verify that a test lamp illuminates between the relay coil voltage supply circuit terminal 85 and ground.
- Connect a 10-amp fused jumper wire between the relay switch voltage supply circuit terminal 30 and the relay switch control circuit. Verify the park lamps are activated.
- Connect a test lamp between the relay coil control circuit terminal 86 and the relay coil voltage supply circuit terminal 85.
- Command the parklamp relay 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 parklamp relay.
| ⇒ | If the parklamp is still activated, repair the relay switch control circuit terminal 87 for a short to voltage. |
| ⇒ | If the test lamp does not illuminate, repair the voltage supply circuit for a short to ground or an open/high resistance. If the voltage supply circuit fuse is open, test the relay switch control circuit for a short to ground. If the circuit tests normal, test or replace the parklamp relay. |
| ⇒ | If the park lamps are not activated, test the relay switch control circuit for an open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If the test lamp remains ON all the time, test for a short to ground on the relay coil control circuit terminal 86 . If the circuit tests normal, replace the BCM. |
| ⇒ | If the test lamp remains OFF all the time, test for a short to voltage or an open/high resistance on the relay coil control circuit terminal 86. If the circuit tests normal, replace the BCM. |
Component Testing
Relay Test
- Ignition OFF, disconnect the parklamp relay.
- Test for 65 to 95 ohms of resistance between terminals 85 and 86.
- Test for infinite resistance between the following terminals:
- Test for less than 2 ohms of resistance between terminals 30 and 87.
- Install a 10-amp fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Measure for less than 2 ohms of resistance between terminals 30 and 87.
| ⇒ | If the resistance is not within the specified range, replace the relay. |
| • | 30 and 86 |
| • | 30 and 87 |
| • | 30 and 85 |
| • | 85 and 87 |
| ⇒ | If less than infinite resistance, replace the relay. |
| ⇒ | If greater than 2 ohms, replace the relay. |
| ⇒ | If greater than 2 ohms, replace the relay. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup and programming |
