I had similar problems a few months ago.....
For me the solution was that there had been a short circuit in the wiring, it was a fairly easy fix. I did not need to change any modules but it did take a few hours to get everything fixed up. I was actually told that the previous owner of the car had tried to put in a car starter and had left all kinds of wire unsoldered and it was a real mess in there. I'm not sure if the solution will be the same for you but i hope this gave you a little insight.