Parking Lamp: Description and Operation

PARK LAMPS
The park lamps system includes the SCM, the EMIC, the FCM, a park lamp relay installed in the Integrated Power Module (IPM), and the left (lighting) multi-function switch on the steering column. The front park lamp and side marker or position lamp bulbs each have a path to ground at all times through their connection to the headlamp and dash wire harness. The headlamp and dash wire harness has takeouts with eyelet terminals that are secured by ground screws to the front end sheet metal within the engine compartment. The rear park lamp, side marker lamp and license plate lamp bulbs have a path to ground at all times through a takeout and eyelet terminal of the body wire harness that is secured by a ground screw to the body sheet metal within the passenger compartment.

The SCM monitors a hard wired multiplex input from the left multi-function switch, then sends the appropriate electronic headlamp switch status messages to the FCM over the CAN data bus. The FCM responds to these messages by energizing or de-energizing the park lamp relay. When the park lamp relay is energized, it provides battery voltage through a park lamp relay output circuit and fuses in the IPM to the appropriate lamp bulbs. The FCM and SCM also send the appropriate electronic messages to the EMIC to control the illumination and lighting level of the panel lamps. The FCM provides a battery saver (load shedding) feature for the park lamps, which will turn these lamps off if they are left on for more than about eight minutes with the ignition switch in the Lock position. The SCM provides a fail-safe feature for the park lamps, which will send an electronic message to the FCM to turn these lamps on automatically if the SCM detects no input from the left multi-function switch.