Here are a couple of visuals you can do:
Check the condition of the wires to the front sensors. They each have an electrical connector below their respective headlight and then the wire runs back along the top of the frame rail before dropping down to the spindle.
Check the front sensors and tone rings for dirt or corrosion build up. For 4WABS 2WD Rangers, the tone rings are in the back side of the brake rotors. The sensors fit through holes in the steering spindles.
2003 FX4 Level II, Supercharged 5.0L V8, Headers, Duals
BW4406 manual transfer case, Aussie Locker, Torsen L/S, 4.10's
Bilstein 7100 rezzies, Cadillac/Mustang rear discs, Duff traction bars
Keypad Entry, Lock LEDs, ABS switch, sway bar discos
Heated seats, Explorer EATC, Trip Computer and consoles
2003 XLT 2.3L M5OD-R1 reg cab beater, 2011 Taurus SEL, 2016 C-MAX Energi Plug-in Hybrid