I have an 08 ES and don't have any problems turning off the ASC. The only thing I'm not sure about is how long to hold the button. I thought it was only necessary to hold it for 2 seconds to turn it off.
Press and hold UNTIL "ASC OFF" is displayed in the dash screen. It seems forever, haven't really timed it but I say it must have been 10-15secs. If you have a watch, you time it and if it doesn't turn ASC off in 2mins then definitely you need your Outlander checked.
Thanks for all the response to my question. As it turned out, that ASC Off switch had been disconnected when the dealer installed heated seats in the vehicle. They reconnected the switch and it now works fine.
Gotta say that these Outlander's are great SUVs....what a bang for the buck!