Similarly to the post below, this thread was very useful in repairing my vehicle. I had exactly the same issue as the original poster (limp home mode, spoiler up, lit up dashboard, OBDII code of P0720 - Output speed sensor).


After replacing the transmission conductor plate (which did not fix the issue) I replaced the abs control module with a second hand unit and the problem went away immediately. For reference, no recoding was required and I managed to slide the unit off the pump assembly and replace it without having to disconnect the brake lines; there was just enough flexibility in the rubber mountings to flex the unit away from the fuse box although I would note that I have a very early model which uses a slightly different unit to the majority of later cars so this may not be possible in all cases


Cheers
Greg