Hi all,
Just bought this beautiful 2005 Volvo XC90, V8, 175'000 miles from my neighbor. She runs great except that while driving yesterday evening, I noticed the AC acting weird and reving up and down without apparent reason. I suspect the outside and/or inside temperature sensor going bad. Maybe the blower? PO changed it awhile ago. Opinions? Suggestions?

Also,
I have the infamous "Alarm System Service Required" popping up on my display every time I start the car. Have read a thread in this forum about replacing the siren to fix the problem, but as another member of the forum suggested, this may need a software upgrade/update from dealership that costs $$$. Without this software update, the car may experience catastrophic failure.

Also,
I also noticed that the message "Anti-skid temporarily deactivated", randomly pops up on my display.

Are all of the above related to this software update? Any suggestions? Fixes?
Thanks