Where is the fuel pump relay located?

Hello,

The fuel pump is located inside the fuel tank. To access the pump, you will have to remove the rear seats.

Also, this vehicle does not have a traditional fuel pump relay, the fuel pump is controlled by a module. Located in the trunk.
I have attached fuel pump and module instructions below. Please note that there are few different options for the module and the pump set up for this S60.

Please let me know of any questions.
Thank you.

https://www.2carpros.com/articles/how-to-replace-an-electric-fuel-pump