Did you have a repeater installed. Found out the hard way that many MH in the 40+ length will need a repeater to pick up the toads signals. With the repeater inplace just starting to unscrew the TPSM from the toads tire sounds the alarm. A good way to test is have system on, loosen the monitor on the toad and see how quick you get the alarm, if working correctly you can not unscrew it fast enough to get it off before the alarm goes off.
2009 Berkshire 390 QS and toad
Retired and traveling