Does anyone know how the tire pressure monitoring system works? Does it trigger at an absolute (actual) pressure level when it drops below it, or does it do a relative pressure level so if one tire is much less than the others it triggers the warning? I assume there is no way to access these pressure readings even if you can enter the car into diagnostic mode, correct? If it is an absolute level that triggers it, like 25psi, is there a way to adjust the level which triggers it? (I have my tires at 40psi, and 39psi and I don't want to wait until the tire gets to 25psi before the warning light comes on.)
In my experience, it triggers in a range of a 5-7% variation across tires, i.e. ~2-3 psi on ~40 psi nominal.
On previous Toyota vehicles I've had it was triggering at about 5# under the initial setting. So if any one tire dropped 5# it would trigger.
What do you mean by "initial setting"? Is that the setting when Toyota first inflated the tires or when the sensors were put on? The setting when I last inflated the tires and then turned the car on? (I inflated them a little too much and then released some air before I started the car so I would think it could not pick up the higher values.)
Thanks. Somehow I missed it in the manual because I thought I looked at it. I looked at the manual online though via Toyota's website which isn't one PDF but sections that jump all around. Thanks,
There's a button under the dash, next to the button that turns off collision avoidance system. That button re-sets the tire monitor for the current pressures, press and hold till you get a flashing indicator on the dash. The spare is not included.
If I'm not mistaken those tire pressure sensors (inside tires) they run on a battery, isn't it? How long do the battery last? I think the battery can not be replaced the sensor need to be replaced.
Right - the battery can NOT be replaced. It would cost hundreds to replace them and then reprogram the car. Has anyone needed to replace them yet? I have read they last 6 to 9 years.
The general rule is to replace them when you replace the tires, but the only thing happens when one goes out is your alert comes on.
I have a low/annoyance-level leaky sensor that the dealership agreed to replace under the sensors' 3yr/36k warranty.
