The service manager said the new IDM had to be "flashed" to be compatible with the power control module...TOTAL BS. I went to the dealer paid my $88 diagnosis charge, went out two my truck, and in 5 min. I was driving home with my new box installed. Apparently this is a very common thing with Power Strokes and they are making a killing at the dealership at $850 per part. YOU CAN PICK THEM UP ON EBAY AS LITTLE AS $150.
Good luck!