Here is some good info, also about over inflation and the TPMS ....
http://www.tpmsmadesimple.com/faq.php
Terry,, on the fords you just need to relearn the system with a hand held remote which is available on eBay for around 10.00.. I can help you do that if you get it..
Over inflation warnings are not mandated by the federal TPMS act ...
But as mentioned by My ModelA::: some may do that... Learned Tire position is also critical on some of the systems