I jsut had my tpms pressures lowed last saturday, I run my tires at 55 and the stock settings worked but while a friend had the computer from ford at my house he lowered the settings. I didnt know you could do it but he did.
to do it you have to have all the computer stuff from the dealership
he then went to the smart junction box
then had to load as built data off of fmcdealerconnect website in to the SBJ
then he could program the tpms to what ever pressure you wanted from 35 to 110.
he could raise the pressure settings with out a sjb reprogram but to lower them he had to reprogram it.
he actually turned the tpms system off of another truck that he was here to work on but doesnt know how he did it, but it is def turned off. I told him if he knew how he did it he would make alot of people happy.