eric1514, Are you asking in regard to the spare or in general? TPMS is radio signal controlled and each sensor is tracked to a location. When you rotate tires the sensor stays with the location or you would have to reprogram. I don't know if you would need a sensor on a spare tire. TPMS is for tires on the road. If you have rear tires different from the front you are going to have to manually adjust the spare tire pressure to match what the sensor is looking for, thus no reason to have a sensor on a spare, IMO. Don't quote me on this as I have not checked but I think TPMS is sold in four tire and six tire (dually) configs and not 5 and 7.
2021 Advanced RV 144 custom Sprinter
2015 Advanced RV Extended body Sprinter
2011 Great West Van Legend Sprinter
2005 Pleasure-way Plateau TS Sprinter