What year Expedition do you have? The 17s have halogen lights.On our Limited, the highs and lows are both LED so I would assume the same is true for the Platinums as well. Most of the time, manufacturers put all the LEDs, drivers and controls in/on the headlamp housing. It concentrates the assembly packaging and also allows the use of the heat generated from all the various components to clear snow and ice from the lenses.