As mentioned, the TST system doesn't notify of lost sensor for approximately an hour. On my 35 foot 5er I noticed one of my sensors not showing the the same temp/pressure swings as rapidly as the other tire on the same side. It's really quite interesting how much things change just based on which side of the rig is facing the sun. Anyway, added a repeater in the fwd bay and it works like a charm.
Make sure you have new o-rings prior to changing batteries as they crumble when you open up the units.