Where is fill plug on a honda accord 2006 ex v6 auto transmission

You should find a 17mm hex-head filler plug on top of the transmission housing, not far from the dipstick. The opening will accomodate a standard long-neck transmission funnel. Afterwards, replace the aluminum crush washer and torque the filler plug to 33 lb.-ft. (45 N-m). Some Hondas and Acuras have a cooling tube that needs to be removed, to gain access to the filler plug opening--simply remove the 12mm mounting bracket bolt and ease out the cooling tube. If you are unsure, you can always remove the dipstick and add ATF there, provided you have a funnel with a small tube (5/16") coming out of it. I've seen people do it both ways.