i believe it only checks for the presence of the TPMS sensors periodocally. ie. it will not throw an error straight away. one possibility is that you fit the new wheels, go for a 15 minute drive, park it back in the garage afterwards (where your OEM wheels are presumably) and in that time it communicates with the sensors on the OEM wheels stacked near the car. you then go for a drive again, then come back, it "resets" again. just a possibility. the other possibility is they are working fine (i hope so, because if so, i will be getting a set!)