Was working in the winter, came on when the cold temps brought the tire pressure down (my old tires with the TPMS were 35" Mickey Thompson ATZ's that I was running @ 30psi).

 

When I had the Mickey Thompson's put on, they were able to re-use the old ones.

 

they don't need to be replaced but when I worked at discount tire we recommended to put new o rings in to prevent an air leak

 

The good news is $80 for 4 TMPS Sensors is a pretty good deal.

The bad news is they are trying to rip you off. Absolutely NO reason to replace them unless they don't work anymore. They will work in all standard valve stems holes, and even if they didn't you could always band them inside the tire/wheel (like I did). New O ring is all that is needed.

As far as the topic goes, the sensors stay activated for quite some time before they go dormant. They effectively shut themselves off to conserve power. It takes wheel motion to activate them again. Mine will stay active for several days. My guess is the logic is for the computer to detect low pressure almost immediately, but loss of signal takes a while before it knows something is wrong. I suppose it is plausible that being in the proximity of a good signal showing good air pressure once a day might keep things happy. Sooner or later your sensors will go dormant, and your computer will figure out it's been too long since the last good tire pressure reading. Then you can enjoy both the dings and the light!

 

Lol, so that how they work.
Thanks for the info...looks like I'll be having to get a Procal as well soon enough.
Still cheaper than the $45/ sensor the tire shop quoted me.

 

That's $80 each with the installation.

 

I installed new tires and it took about a week (about 100 miles) before my TPMS light came on.

On the other hand I lowered the air when I first got my JK to see how accurate it was and when it hit low pressure it tripped immediately.

 

There are a lot of theories to how these damned things work. Last year I (barely) scraped one on a rock, causing a flat. I had a tire shop (Thanks Chip!) put a rubber one in to get me back in the trail and placed the bad sensor in the center console. I ran for a while aired down then filled up and the TPMS light went off.

For the longest time, with the bad sensor in the console, I had no TPMS light. Then one day it went on and no matter what I did to the tires it wouldn't go out. It drove me nuts for months until one day I jacked all the tires up to 38 psi and it went out. It has been out ever since. The bad sensor is in a box somewhere in my new house, but far enough away from the jeep in the garage that it can't be picking up a signal.


So.... what does all that mean? Well, it means the one being out of a tire didn't set TPMS off for a long time. Then it went off and finally airing the tires up got the light to go out. Right now one sensor isn't even near the jeep and there's no problems. Logic dictates... that there's no logic in this. Maybe if the stupid system was useful and would actually register to specific tires and give their pressures it would be worth the money. As it is now it's a gov't mandated piece of crap.

 

Nicely put!
Yup, seems like just another way to squeeze a couple more bucks outta our pockets

 

I wonder if I remove the 4 in the driving tires and keep the one in the spare and aired up to like 35 PSI if that will be enough to keep the light and ding from going off? ( I will keep the four not being used in a trash bag which will be in the local land fill)