I responded to another post about an S70 stall, which is very similar to my problem.

My '04 S60 has stalled 4 times since spring. Each time it has happened with my foot on the brake going around a turn. The first three times the car had been driven for 1/2 hour, the last time 10 minutes before the stall. It has happened turning both left and right. I had it at the dealer again today, with no solution or idea for a fix as "the computer is not diagnosing a problem," and it cannot be duplicated. When I have to grip my wheel at every turn with a fear the my power steering may go out, there is definitely a problem. I did have the fuel pressure sensor replaced in '07.

Having no answer again today, is very frustrating. What can be done or who should I be contacting? Based on other posts, it doesn't seem that stalling is a uncommon problem.

 

That problem happens to me occasionally. Do you have a manual transmission? In my case I release the clutch during braking, car is in neutral. As I am applying the brakes the RPM's start to descend below 500. The car starts to rattle like it is going to stall and sometimes it does. What I have noticed is that if I take a turn while I am applying the brakes the car will stall
more often. If I apply the clutch at the same time as I am braking then there is no stall. My check-engine light went on roughly at the same time as this started happening. My mechanic scanned it and said there were two errors that showed up. One showed that there was a problem with the computer-probably due to humidity. And the other showed a problem with the air sensor. He reset the computer but the problem hasn't gone away. Now is it a computer malfunction or an air sensor problem? Could this be your problem as well. I am searching the forums at this point trying to find some sort of answer before I commit myself to fixing it. Good luck.