Tesla changed the entire Tire Pressure Monitoring System (TPMS) starting with VIN 50900, around September 2014. Cars prior to this VIN have an older system that is unable to display tire pressure in the car. It still will warn of a tire with low pressure.
The sensors have a small non-replaceable lithium-ion battery that typically lasts 5 years. Once the battery expires the sensor must be replaced. The sensor measures tire pressure and temperature. Each sensor for each tire costs about $50.
VINs prior to 50900 use the Baolong sensor, Tesla part number: 1010938-00-B
VINs at 50900 or later use a Continental sensor, Tesla part number: 1034602-00-A
The sensors only transmit data. The receiver only works with a specific sensor. If you have an older car, you cannot just replace the sensors. You need both the new sensors and a new receiver.
One user got a quote of $1100 to convert to the new system. When I asked our local service, they thought it couldn’t be done, so your mileage may vary!
Good info at the bottom of page 1 in this thread. Possible to have done at the Service Center and less expensive if you have Gen 2 wheel sensors already (3rd party or if you bought wheels with them, etc.):