The provided Freightliner tire pressure display works fine, however it will not read pressure prior to leaving out for the day, the tires have to be rolling for a period of time. Regretfully, the display is horribley small and somewhat clumbersum to move through the tires. A good practice is to turn on your parking lights to illuminate the display during the day.
In any case, it does work well and will warn you with a flashing light and beeping sound should a tire have heat or pressure issues.
My favorite TPMS is the Tireminder unit, they make a stand alone and an Iphone version. My phone sits in a holder and the large display rotates though all the tires showing pressure and temperature You can find a review on my personal web site at RVVOLT.COM