We know that in the absence of TPM valves the warning lights come on. One can be reset while the second stays on at all times.

If only one wheel were equipped with a TPM valve will the warning lights still activate?

What if one TPM valve were just carried inside the car?

The system would be reset once and be satisfied thereafter or is the monitor smart enough to count to four and need to see some pressure?

Somebody has a car without TPM valves and could take a valve or a TPM wheel for a test ride?

 

it should give you a warning if one is missing. also you cannot trick the system by taking out one monitor and keeping one in the car because it senses the tire pressure, and it wont sense any pressure if you have it outside. i suppose you could theoretically reset the TPMS system so that that one uses 0psi as its base pressure, but i dont know what that will do.