George, thats exactly correct but the condition of both batteries probably would never happen... The two wheels that have no sensors would never be sending a low or critical condition in regards to the pressure (psi), so while driving no signal would reach the TPMS receiver so there is nothing for the receiver to process. No signal, no triggering of the lamp. Kapishe(sp)?

Going out on a limb here, I think the TPMS sensors in our cars wheels only transmit a low or critical PSI signal. The registering/programming is there ONLY to help jack up the price (diagnostic) that the tech charges you to locate the errant sensor(s). They have to generate $ for those damn machines, just another way to bend you over in my opinion. Thats why when my sensor battery(s) start triggering due to some crazy reason, I'll be pulling that receivers positive power pin and tucking it up with tape on it. Also, there is a diagnostic feature on this setup, as when the indicator lamp on the dash flashes repeatedly (about a minute I think), and then stays lit, it means something is wrong with the TPMS system. It does not necessarily mean a tire is low. In this condition, it would be prudent to do the pin removal mod as that would be very expensive to fix. Oh, a footnote, if you do the power pin removal thing, and the TPMS light does not reset after a while, you may have to either get the light reset (dunno if a standard OBDII tool will work or not) or suspect something other than the TPMS is causing the flashing lamp on the TPMS circuit. There are a few (if not many) things connected to the trigger output on the TPMS bus.