How to deal with tire pressure sign on my dashboard

Disable it

 

If you haven't recently had tire work done, something that might have messed up the sensor, then it's likely a failing battery on a sensor. The sensor batteries are not replaceable; to remedy you'd need to replace the sensor, and get it initialized.

If a tpms warning light will not fail you at a some annual inspection. it's up to you what to do. Personally, I'd just ignore it.

 

Once you inflate all tires to your desired psi, just press and hold the TPMS button until the “sign” flashes 3 times then let go. If nothing is wrong with the tire sensors and everything else, the light will go away. When a tire is below 25% of your set psi the last time you held down the tpms button for 3 flashes, the sign will come back on. If after 3 flashes and it still stays on, or comes back later in the week and all tire pressure are still holding, you’ll have to look further to see what else to troubleshoot

 

Does this work for Gen2 Prius too?

 

repeat post deleted

 

That my friend will be a question for gen 2 sub forum

 

Did you check ALL of the tires.....or did you stop when you found the first one low ?
When that tire was fixed, did they also give you a new valve stem ??

 

Where is the TPMS button on the Gen III?

 

Before you do that.........
You MUST be sure that all tires have pressure transmitters AND that all tires are up to the proper pressure.

 

The TPMS button under the dash is just a way for you to tell the system what pressures it should consider "normal". The idea is you pump up the tires to the pressure you want, then use the button, and it sets the warning threshold some fraction below that.

The warning threshold gets set quite substantially below that pressure. They do that so you don't get flashed every time there is a sudden cold snap outside, and so that, if the warning has come on, the ECU can definitely notice when you have reinflated to the normal pressure, because it will be a big difference.

The disadvantage, in my mind, is that the warning threshold ends up being somewhere way down in the twenties, probably low enough you might already be damaging the tires by the time the light comes on. I deliberately set mine higher, by inflating the tires up to the max sidewall pressure, holding the button to remember that pressure, then letting the tires back down to my usual pressures. That means I will see the warning at only a few pounds low. I will get a warning if the weather turns cold, but I don't mind that. If the forecast doesn't say it's warming up again, I'll add air to get the right pressure for the colder season.

The disadvantage there is that if the warning comes on and I add only a few PSI to get the right pressure back, the ECU won't immediately turn the light back off. It can see a few pounds of variation just as possibly being normal driving/cold variation. Doing a Techstream TPMS Signal Check will turn the light off if I'm impatient, or it'll generally turn off by itself in a day or two.

The light can also mean that something else is wrong with the TPMS. The reasons can be read with Techstream. (In Gen 3, IIRC, and earlier, they can also be read using a jumper wire and blink codes.)