How does the TPMS work on my 07 F150? HOw does the signal get fomr the wheel to the trucks computer?

 

I believe it works on the PFM principle. Pure Freakin' Majic!!
Sorry, I couldn't resist that. I believe it's just a radio signal.

 

There are remote receivers that receiver a signal from each of the sensors that are mounted on each of the wheels. The tires must be spinning in order for the TPMS to work.

 

They monitor the pressure in the tires through sensors located in the tires,which is called a direct system, or the use of wheel speed and other sensors on the vehicle,this is called the indirect system. The info. that is collected by the sensors is transmitted to an on-board processor that interprets the sensor signals.

 

It also sends signals in 2 different modes. Driving above approx 20mph and parked. In the driving mode it sends a signal every 60 seconds. If it doesn't receive a signal after about 20mins, it turns on the light. In the parked mode it sends a signal every 60 mins (to save the batteries), It will turn on the light if it does not get a signal longer than that (not sure of the interval) or if it has a low pressure condition. I did not learn this until later and built a pressurized tube to hold the sensors as I have 2 sets of tires and wheels, summer and winter. Unfortunately it works for only 20 mins while driving.