I've been having a problem with a tire pressure warning that shows up intermittently while driving. The tire symbol flashes and message center gives a "tire pressure sensor fault" indication that will eventually clear itself after a few starts.

I do have a full size spare on an '05 factory rim that I am rotating thru the tire positions that does have the sensor installed. My Ford dealer was not able to provide an Eco Plus tire, so I had to purchase it and have the sensor installed at a local tire dealer. I gave them the sensor mounting band and instructions, but didn't verify the installation myself. The problem started after the spare was installed.

I have had the dealer try to check the problem, but they've told me that the alarm is not stored in the computer's memory and their suggestion was to add air. I've also had them reset all of the sensors the last time I had a rotation done, but it hasn't helped.

I am now wondering if the sensor was installed wrong by the tire dealer, but I am hoping for some advice before having the tire demounted. Also, can the sensors themselves be checked to be functioning correctly some other way while still on the car?