tire pressure monitor 101

[gvidas]

Just got back from 30k service at a dealership. ~50mi away from their shop, my tire pressure light starts blinking. Five more miles and it goes on steady. It had been on for a while before I went in for the regular service, and I had assumed one of them was de-synchronized or whatever because I had to replace a sensor after splitting a valve stem trying to get the chrome caps off during the winter.

So, my questions are:

- What does the tire pressure light actually mean? Is it comparing current pressure to a set standard, or some relative change off a calibration point, or is it just saying "one tire is much lower than the rest"?

- What's the margin of acceptable variance from tire to tire? I bought an old fashioned dial indicator and it showed ~3-4psi difference between all the tires (this at about 70mi away from the dealership.)

- Previously, I've re-inflated tires and not seen the indicator light go off. How is this thing meant to be used? Can I just disable it and be proactive about tire pressure? It mostly seems to make me lazier, all "oh well, it's blinking now, whatever; it did that for a while before, too." Another latent bit of guilt, all oh hey another dash light is on.

Thanks.

(edit: 2007 4wd accesscab v6)

[bajamoon]

first, did you check your spare tire, and did you push the button down below the steering wheel, that will reset the monitor. I think the light will go on with a vairience of 5 psi. I would check your spare then push the button below the dash, it's next to the hood release. It's going to blink everytime you start the car, just put a black piece of electrical tape over that light like i did.

[FoxySandChick]

Originally Posted by gvidas

Just got back from 30k service at a dealership. ~50mi away from their shop, my tire pressure light starts blinking. Five more miles and it goes on steady. It had been on for a while before I went in for the regular service, and I had assumed one of them was de-synchronized or whatever because I had to replace a sensor after splitting a valve stem trying to get the chrome caps off during the winter.
Did you get the new sensor programmed at the dealership?

I can't remember at the moment and don't have my manual, but flashing might mean there is a problem with a sensor...?
So, my questions are:

- What does the tire pressure light actually mean? Is it comparing current pressure to a set standard, or some relative change off a calibration point, or is it just saying "one tire is much lower than the rest"?
It is comparing current pressure of each individual tire to a set standard which can be changed by putting the desired psi in all tires including the spare and holding down the 'set' button until the light flashes 3 times and
- What's the margin of acceptable variance from tire to tire? I bought an old fashioned dial indicator and it showed ~3-4psi difference between all the tires (this at about 70mi away from the dealership.)
it goes off when 1 or more of the tires drops more than 25% from the psi it is set to recognize
- Previously, I've re-inflated tires and not seen the indicator light go off. How is this thing meant to be used? Can I just disable it and be proactive about tire pressure? It mostly seems to make me lazier, all "oh well, it's blinking now, whatever; it did that for a while before, too." Another latent bit of guilt, all oh hey another dash light is on.
Did you also check your spare?
It can not be disabled, but there is a cheap mod that entails placing a piece of electrical tape over the light on the dash
Thanks.

(edit: 2007 4wd accesscab v6)

Also...
http://www.tacomaworld.com/forum/tec...ting-tpms.html

Can someone else clarify...flashing tpms=problem with a sensor?
Hope this helps and I'm sure others will chime in.

Edit: checked the owners manual....and blinking tpms light means there is a problem with the system which would need to be checked at the dealer.
Page 164 in my manual....under the section that explains all the dash warning lights.