This definition appears very rarely
From 1999-2002 model years the 2H mode was dropped and the system was only 4A, 4H and 4L. From 2003-onward model years the system regained its 2H mode. What are the modes, and how do they differ? (note this is the operational behavior of a 2008 Ford Expedition. Newer and older Expeditions will vary only slightly) ? 2H 2-wheel-drive with high range gearing (1. 00:1) Rear-wheel-drive capability, 2-wheel electronic traction control.