I just spent some time with my very smart INDY. We talked about what could be wrong. I mentioned that I could not get a continuity check through the module switch contacts shown in the diagram in post #6. He said you're not supposed to. You have to have the wheels spinning to get a signal from the wheel sensors. So we hooked up his very expensive scanner looking at all four wheels at the same time and reading the signals through the computer system. I then went for a drive and watched all four wheel signals showing up just fine and all four essentially just alike. So, as far as I'm concerned that sensing system is working just fine all the way through the computer.

I would like comments on this new data.

The next thing is to start checking function of the pump. And if that checks out then the module itself must be the problem. I guess it could be something in the relays or a bad fuse. I'll check all those next.