Tire pressure monitor system problem

I have a 2008 Avy and after about 20mins of driving, the TPMS light comes on and it says my Rt front tire has 1 lb of air. I took it to a local tire place and they reset the system. Told me it was registering 2 left front tires only...light went off. Next day, after 20 min drive home from work, TPMS light comes on but now it says left front tire! Went back and they reset again, but light stayed on. They said there were no errors when they checked it. Funny thing is, it only does it when the temp outside is above low 60's and almost exactly at the 20 minute mark on my drive home every afternoon, not in the morning when it's cooler. I've watched the pressure fluctuate on the display and it'll get to normal and go off, then drop to zero and come back on.

Thoughts?

Know if these are the original pressure sensors? Sounds like they're dying. Had something similar happen when mine started to go, they showed the wrong pressure and sometimes -- (dashes) and then randomly come back to life later and of course, one finally failed for good forcing me to get them replaced.

I think they are. Just seems odd that after reset, went to other tire and the very specific temp and time involved. But could be, thanks! Did you replace all 4?

Since they are all probably the same age, I would replace them all together.

That will keep you from having to keep up with where the "new" ones are later on, as well.

From what I've heard, a four to six year life expectancy would appear to be normal.

I replaced all of mine (because there were none installed) when I bought my EXT back in 2012.

I guess we shall see how that 4 to 6 year thing plays out.

Agreed. Mine lasted about 8 years. Definitely replace all four. It's a fairly quick process for any competent tire shop to do.

you can get them from E-bay and then have a tire shop replace them at next rotation!

Didit

So, had all 4 replaced...lights went off for one day, then right rear sensor said 0! Went back to tire shop and they said that tire wasn?t sending info now. They still had my old sensors and checked all 4, they all worked! Anything else I can do? Can this system be turned off?