Wheres the ECU in Volvo S80? - Boltar
Anyone know where the engine control unit on an S80 is located?
I've looked in the engine bay, in the passenger compartment and
in the boot but can't find it anywhere.

Thanks for any help.
Wheres the ECU in Volvo S80? - Martin Wall
Well based on the info I gleaned from the links in the following thread

www.honestjohn.co.uk/forum/post/index.htm?v=e&t=27...9

I believe that it is located as follows (*if* it is the same as the V70):

open bonnet
standing in front of car you should see a black box on your left with a nozzle at its front (washer bottle top up infront of this)
I believe that the ECU is in there BUT it's late and I'm tired so I could be wrong!

Good luck anyway...
Wheres the ECU in Volvo S80? - Aprilia
IIRC the ECM is located on the offside front inner wing between the washer bottle and the coolant header. It may be under a large cover.