transfer torque, and LSD will function like an open-type differential. The front differential on four-wheel drive models are open-type differential. The AdvanceTrac electronic stability control for the 2003 model year. The Traction-Lok option was dropped after the 2006 model year, but a limited slip differential was reintroduced during the 2015 model year.Electronic traction control (2003–present) AdvanceTrac electronic stability control was introduced for the 2003 model year as an optional extra on the second generation Ford Expedition (U222). Bundled with the electronic stability control system is four-wheel electronic traction control (functions at all wheels) for Expeditions with four-wheel drive. Two-wheel drive Expeditions only receive two-wheel electronic traction control for rear wheels. AdvanceTrac was made standard equipment on all third generation Expeditions (U324). The traction control system uses four-wheel, four-sensor, four-channel anti-lock braking system (ABS) to apply and release the disc brakes on the drive wheel that has lost traction. The ABS clamps down on the slipping drive wheel or wheels, "brake locking" the differential, which can transfer up to 100 percent of supplied torque to the opposing drive wheel with better traction. By ABS "brake locking" both the front and rear differentials, the traction control system can simulate front and rear differential locks. The system works even if two of its drive wheels (one front, one rear) are completely off the ground. Using the ABS brakes rather than mechanical limited-slip or locking devices inside the axle differentials gives quicker response, more seamless performance, and enhanced durability. Terrain Management System (2018–present) Starting with the 2018 model year, the Expedition and Expedition MAX will utilize Ford's Terrain Management System. Buttons to control the 4x4 system are arranged around the central Terrain Management dial. The system is similar to the one found in the 2011–present Explorer, however the Explorer's system is more simplified. The Expedition's Terrain Management System is adapted from the SVT Raptor to allow use of a 4L (low-lock) mode as well as an electronic locking rear differential. Moreover, the Explorer's Terrain Management System has 4 (four) drive modes, while the Expedition has 7 (seven) drive modes, not including the 3 (three) 4x4 system direct drive modes. Depending on the mode selected, Terrain Management will control, adjust, and fine tune the engine, transmission, center multi-disc differential lock, throttle response, four-wheel electronic traction control and electronic stability control (ESC) to adapt the SUV for optimal performance on the corresponding terrain. Towing capability When