An excerpt from the CleanMPG glossary:
Forced Autostop: A Honda hybrid will AS (Autostop) in various scenario’s although it is very limiting to a given condition. To high a speed, to cold, not enough SoC (state of Charge), not enough speed since last AS, Defrost or A/C on except for the AH and HCH-II in specific conditions, etc. will not allow AS … Forcing an AS, aka Fas , takes these limits out of the equation.
http://www.cleanmpg.com/forums/gloss...earchoptions=1