My tire pressure monitoring does not seem to be working, never get a tire pressure low warning and checked my tire pressures this morning and they were at 37, had them set at 42. Do I just reset the sensors on the screen.
The tire pressure sensors do not replace a real pressure check. They are there to tell you if your tire is going flat. By the time they alert (generally 25% low), there is already damage done to the tire. In some cars, you can up the pressure and then reset the sensors and then lower the pressure so that they will alert when you're only slightly low. I don't think that the Tesla's reset function will do that (but I haven't actually tried).
Service can customize the threshold pressure, and 37 might not have triggered it. You can test it by letting a little air out of one tire to see if the warning goes off. There are several levels of warning depending on how low the pressure is.
My understanding is that the sensors are sending actual PSI values and the threshold for turning on the warning is configurable in the car's software.