If and its a very big if, you knew someone handy with a soldering iron you can remove the ECU and open it up, look across the printed board and find the faulty solder joints, i work for a Volvo indy (not for much longer) and the V40's and V70s use the same ECU, we have never had to replace them as its always a break in a solder joint or 2, but if its still under warranty then id leave it to them to fix mate