Overview: Recently swapped winter tires on a set of wheels that had functioned previously on the car, but after the swap, the TPMS won't reset. At first it indicated "Inactive". That later disappeared and when tapping the stalk the "reset" button appeared but the system does not reset and the flat tire light remained. Once again however, the "inactive " light has reappeared and the flat tire warning light flashes then remains lit. Details: The tire pressure is correct The old tires, 225/50 17s, were on a '13 335i. I put them on the 135is and successfully reset the TPMS. However the tire aspect was too large for the car and ordered 215/45 17s from Tire Rack. Recommended installer swapped the tires and away I went. Before long the warning light comes on. I pulled over to reset the system and it reads "inactive". Eventually the inactive light goes away but system still won't reset. I take the car back to the installer who plugs in the OBD system looking for a faulty sensor. From previous posts about this problem, it was stated that sensors can crack or become inoperable upon tire change. According to installer all sensors are working. His advice: Don't worry, it'll go away. Inactive light subsequently returns. Thinking perhaps the sensors are not the correct ones for the car, I find sensors from various suppliers that are identical and fit both cars. 433 mhz. I call Tire Rack tech support and they tell me their product number is slightly different, S184 for the 3 Series and S182 for the 1 Series but they are virtually identical and should work. As mentioned above they did work with the previous tires. One post said to disconnect and reconnect the battery. That did not work. Other posts addressing this problem indicate a possible electrical problem as the remote function of the key also fails to respond. I have not had that problem. Any insight would be appreciated. I have not reinstalled the summer tires to test if the TPMS is functioning correctly because it is too damn cold outside. In other words I can live with the light on until April if that what it takes.