read your owners manual, page 221
The electronic locking differential can provide additional traction should your vehicle become stuck. You can activate the differential electronically and shift it on the fly within the differential operating speed range. The differential is for use in ice, snow, mud, rocks, sand, or any off-road condition where you need maximum traction. It is not for use on dry pavement.
• In 4x2 or 4x4 High modes (any gear on 2WD), the electronic locking differential will automatically disengage at speeds above 25 mph (41 km/h) and will automatically reengage at speeds below 20 mph (32 km/h).
• The AdvanceTrac system has the ability to take over control of the electronic locking differential and disable it during driving maneuvers when necessary.
