I'm still experimenting with mine. I even took one of them completely apart. Not a good idea! They are sealed and have itty bitty surface mount components around the edge, the size of a pinhead, begging to be stripped off.

One thing that I noticed is that the battery seems to fit pretty loose. So I stuffed a piece of plastic foam in the holder to put some added pressure on the battery.

Right now, both of my sensors will react just moving the bike in or out of the garage. I'll have to keep checking for inconsistencies ...

Check your temps and your pressure. The temps can change even when the pressure does not, indicating a good sensor response.

"--" is definitely not good! Try the foam?

Another thought: Radio interference - the amp is in the way. Try it with and without the radio on?