Hi you can try to clean the air temp sensor by vacuming it and then resetting car by removing battery negative lead for 6hr minimum..car will run rough at first but will re-learn in few hours...when you first put key in and switch car on turn fan to full for few seconds and then off repeat afew time...

Check your alarm sensor in panel o the roof of the car its located toward the centre..it may have come loose and be rattling about..this item has been known to fail..

Abit late maybe but try cleaning out the EGR mixer and plenum..you willamazed at the crap you'll find in there..i willput some picsup to give you ideaof crap and the location of mixer which is the alloy part http://i97.photobucket.com/albums/l204/s60mbs/other%20pics/DSCN1154.jpg http://i97.photobuck...

thisperson hasspammed other volvo forumstowoth exactly the samething