Circuit/System Description
WARNING: This page is about a different car, the 2007 Suzuki XL7. However, it is still accessible from the selected car via links, so may be relevant.
Voltage is applied at all times to the Park Lamp Relay from battery voltage. When the headlamp switch is placed in the PARK position, ground is applied through the park lamp switch signal circuit to the body control module (BCM). The BCM then applies a ground to the park lamp relay control circuit. This engages the relay that is soldered to the underhood fuseblock circuit board and applies voltage through the park lamp fuses and to all the park lamps.