What other systems in car does the tpms feed, abs... traction control...or nothing? Also I ran for a month with no tpms in rears and got the appropriate light, then something changed and light went out. Put wheels back on with orginal tpms and no light, even with 25lb pressure. Factory setting was 30 lb and it appeared to be very sensitive coming on with only a couple pounds low. So what is the low side set at?