I have a 1996 mark viii with a check engine light that won't go off! I had the ecu checked at a lincoln dealer and it said I had a problem with code #720. That is the output sensor on the transmission which is not making a complete circuit. I had the ecu replaced( flashed) installed but the check eng. light is still on? The input and output sensors have been replaced along with both oxygen sensors. What else can I do to get this fixed?

I'm sure the two are at the crux of the problem, but what and where do I go from here? what about the output sensor? Why is the ecu not getting a signal back from the sensor? Do you know of anyone that has had this problem? Let me know, Thanks joag5252

check www.markviii.org they have answers to most questions, if you cant find it just ask, and users will be happy to help you out

Hard shifting indicates a needed transmission 1-2 shift accumulator piston and spring replacement. Do this simple fix if you are experiencing shifting problems. It may be a good idea to do it even if you don't have problems yet, as the bore gets worn from the original parts. Click this link for accumulator replacement instructions (with pictures) and part numbers: http://www.markviii.orgLOD2part_numbers.htm#Spring