'09 FX4 manual says when you are in EDL (diff lock), if in HI range it disengages at 20mph and in LO range it disengages at 56mph. Seems like the numbers should be reversed. Also, does anything let you know if the locked diff does disengage, as I was at about 25mph in HI, but the indicator light just stayed lit--no blinking or anything to say it dis-engaged. Didn't even attempt the LO range limit according to the owners manual. Thanks

 

I thought the same thing-who would take their truck up to 56 mph in low? When mine disengages, the little icon next to the switch blinks.

 

Trying too remember from the last time I took it out at the outer banks. I believe mine shows an X on the rear differential when its engaged and should just turn the X off when disengaged (however I think the the **** stays pulled out and you have to push it back in and pull it back out to reingage it). And I thought it disengaged at 25mph, been a while since I looked at the manual.