Parking Lamp: Description and Operation

The park lamps system includes the EMIC, the TIPM and the headlamp switch on the instrument panel. The front park lamp and side marker 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 right (right park lamp and side marker lamp bulbs) and left (left park lamp and side marker lamp bulbs) inner fender support within the engine compartment. The rear park lamp, side marker lamp, license plate lamp and the optional fender and tailgate marker lamp bulbs have a path to ground at all times through a takeout and eyelet terminal of the headlamp and dash wire harness that is secured by a ground screw to the left inner fender support within the engine compartment. The optional cab clearance lamps each have a path to ground at all times through a takeout and eyelet terminal of the instrument panel wire harness that is secured by a ground screw to the back of the support structure of the instrument panel near the center.

The EMIC monitors a hard wired multiplex input from the headlamp switch, then sends the appropriate electronic headlamp switch status messages to the TIPM over the CAN data bus. The TIPM responds to these messages by providing a battery voltage output to the appropriate lamp bulbs through the right and left park lamps feed circuits. The TIPM 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 EMIC provides a fail-safe feature for the park lamps, which will send an electronic message to the TIPM to turn these lamps on automatically if it detects no input from the headlamp switch.