Chainguide
Member
I doubt sincerely that the dealer did anything to the truck programming to disable ASS and despite the menu option with misleading verbiage, that setting does not survive an ignition cycle. This is an economy/CAFE “feature”, and I use that term very loosely. More than likely, your observation of the truck not automatically shutting off was coincidental.
Sync doesn’t control, or have anything to do with the ASS, completely separate modules in the truck.
There are multiple ways to disable ASS on the fleet of Ford vehicles, ranging from simple wire jumper on the manual switch, pull the wire from the harness, jumper the trailer harness(?) Forscan, or buy a module for the switch that ‘defaults’ the ASS to off, but allows you to enable it manually - the opposite of what Ford does. CJ Pony parts sells one that’s plug and play for the switch, Forscan turns it off completely.
What you are saying sounds like it would make sense, however I went at least 6 months with countless ignition recycles and and the switch would default as "off" upon start up. Trust me, I know the difference.