It's a small sensor, often with a single wire connected to it. You'll likely need to get under the truck to find it. Look carefully around the top of the differential; it might be near the axle tubes or toward the rear of the differential.
Important Note: Before you start searching, it's crucial to consult a repair manual specific to your F-150's year and model. This will give you the most accurate location and avoid any unnecessary disassembly. A parts diagram from a reputable online parts supplier (like AutoZone, Advance Auto Parts, or others) showing your specific truck's differential might also help visualize its location.
