Following is a link to a function diagram of the older "fuel pump relay" and the newer "MAS". They look quite similar to me so far as what all they do. But the old term "fuel pump relay" was not accurate as it also does other things like activate cold start, limits engine speed, and transmission kick-down cut-out (at higher RPM's).

I think they may have changed the name to MAS (Engine Systems Control Unit) as that is a more inclusive description?

http://www.startekinfo.com/StarTek/outside/12264/Program/Engine/103/07.3-0013.pdf