4hi no worky... any ideas?

[rdwngs444]

my electronic 4hi doesnt engage, the dash says 4hi and traction control turns off but the front wheels dont engage. 4lo works like normal when the hubs are turned. Any ideas as to why 4hi doesnt work?

[rdwngs444]

turns out its the vacuum line to the 4wd, ford is going to look at it in a couple weeks when my extended warranty takes effect.

[Jarrod B]

they are still using vac lines to the hubs on a 08?