tire pressure gauge

You will have to take this back to the dealer. A common problem is that the tire pressure monitoring sensor is damaged when the tire is put on, since they are mounted right behind the valve stem. A dealership will be able to check to make sure that the sensor is working properly and communicating with your system.

if you replaced it (the sensor) then all you have to do is drive the car for 2 miles at a speed of 15 to 20 mph, and the sensor will automatically register to the car. don't go faster than that (it will not speed up the process) if you kept the same rim. if you put on like 19's then your f*cked.