Excuse me for my ignorance about this topic. My rear right tire has a small piece of metal embedded in it and causing a slow leak. So, yesterday I swapped it out with the spare tire so I can have the tire shop fixed it today. Before installing the spare, I checked the spare's pressure and it showed 40 psi on my tire gauge. After installing the spare, the truck's TPS showed that tire at 35 psi. It showed 35 psi before leaving my driveway and I got the tire pressure sensor fault message popped up about 20 minutes later when I was almost to work. So, where exactly is the sensor? Does spare tire have a sensor? How does the sensor communicate with the truck computer if it's inside the tire? Can I trust the tire shop to properly put the sensor back in place after fixing the tire?
I took my wife's 08 Edge to have one of the tire fixed and got the tire pressure sensor fault afterward. We didn't deal with it and traded that car in about a month later.

 

The sensor is in the tire you removed. There is not a sensor in the spare.

These systems have been around for years so any good tire shop should be able to repair or replace the tire and have the sensor remain operational.

 

The sensor is actually part of the valve stem. The sensor part of the stem is inside the wheel. Spares almost never have them.

My dad has a spare set of wheels with winter tires that do not have the sensor for his 09. He just lives with the low tire warning all winter. I imagine it is more annoying on our newer trucks as his is just a light on the dash.

 

Right. The fault occurred after driving and the truck finally noticing the missing tire. Once you either swap it back, or put a new tire on that rim, the message will go away once you drive another 20 minutes or so.

 

How do the sensors communicate with the truck?

 

RF

 

There is a tiny little cellphone in each wheel that calls the truck and tells it the pressure...

 

just throw the flat one with the sensor in the back of the truck.

 

That has been proven to not be a solution, the lack of movement will turn off the sensor eventually.

 

I think it will take a while for the sensors to lose power. My winter wheels don't have the sensors but I store the summer wheels (with sensors) in my garage next to where I park the truck. The truck re-connects with them every night and then starts complaining 20-30 minutes after leaving the garage. On my 2010 I could ignore the warning but my 2016 is such a PITA about it that I am going to spring for another set of sensors this winter.