Headlamp Leveling Switch - Operation - Export

OPERATION

The headlamp leveling switch receives a battery voltage input on a park/tail/running lamps feed circuit whenever the exterior lighting is turned ON. It then provides outputs to the Totally Integrated Power Module (TIPM) on a headlamp leveling switch to module signal circuit to control the headlamp leveling function. The switch receives a path to ground at all times through a take out and eyelet terminal of the instrument panel wire harness secured to the instrument panel support structure.

The switch illumination level is controlled by a Pulse-Width Modulated (PWM) output received from the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN) on a panel lamps driver circuit. The EMIC controls this output based upon the panel lamps dimmer signal circuit input from the panel lamps dimmer switch.

Each switch position selects a different tap on a series resistor within the switch to provide the appropriate resistor multiplexed output to the TIPM over the headlamp leveling switch to module signal circuit. The TIPM reads and responds to this input by providing the appropriate control outputs to the headlamp leveling motors.

The headlamp leveling switch as well as the hard wired inputs and outputs of the switch may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information.