Well first off, check the code and see what it says.

Another thing you can do is remove and inspect the ECU (15 A) fuse in the under-hood fuse/relay box. If that is bad, replace it. Then inspect the ACG (S) (15 A) fuse in the under-dash fuse box.

It is possible that it could be your ECU, but probably unlikely.

Here are some pictures from the service manual that might help you. They are for trouble shooting when you don't hear your fuel pump come on. You will also see a picture of there the "main" relay is.