Today while going to work, the tire pressure warning light came on. I checked the tires...they seemed fined. I reset the thing and went to work. Coming home , after driving for 15 minutes, the same thing happened. I brought it to the dealer and he said that the fronts were 3 pounds more than the rears. I told him that is what Scion recommends.. 32 front 29 rear. He checked the tires and rim. They seemed ok. He reset it and the same thing happpened. He changed the pressure in all of them. He made them all 30 and the light stays off now. He told me he will discuss this with Scion and get back to me. By the way, today was the first day that the temperature got above 70 degrees since I bought the car. I wonder if this is a factor???

 

HMMMMMM probably...it must have seen an increase and must have thrown it off.

 

Temperature should not affect anything, not on our car's sensors. Our sensors work via the ABS to determine the speed of each wheel, and if one is travelling slower than others, it will go off. Eventually all cars will have actual microelectromechanical sensors placed inside of the rims to determine actual pressure, however for right now only more expensive cars use that system. The downfall to our system is that if both wheels are under inflated on one side, or if all tires are underinflated, it won't pick it up, so proper checking should still be maintained. Hope that helped, I could pull up a few articles if you need it.

 

microelectromechanical WHOAH MY HEAD HURTS NOW!

 

Awesome

 

mines kept goin off too. it could be that i have one hankook tire and 3 potenzas. i set it to 33 all around.

 

The difference in pressure has nothing to do with it. It will calibrate to whatever the diameter of the tire is, then if that changes it will set off the warning. 30 pounds in the front is simply too low in a tC. You'll get worse fuel economy and have a high risk of damaging a tire or wheel. I would go back to the dealer and complain. (Did a service tech do this for you? Or a salesman? A salesman I can understand, but it's unforgivable for a service tech to do something so blatantly wrong.)

Anyway, you probably did not reset the system. You need to hold in the reset button until the dash warning light blinks three times.

 

same thing happened to me, except i haven't tried making em all equal yet. light comes on every 15 minutes , i just ignore it now....

 

to those that are rocking 18's, what is your tire pressure set at..........

 

I had one wheel that was noticably off and the light never came on.... kinda weird.

Rivulent, I don't know how the tC's tire sensors work, but temperature does affect some cars and the light. My Mazda 3's light will turn on in the morning and after a few minutes of driving it will go off when the temp goes up.

 

He is right, although 'micromechanicalsensors' may be exxagerrating a wee bit. Think of a sensor about the size of a travel size deodorant. Its a bit smaller then that. At least the ones I have seen are about that size. They will eventually be enforced for all cars to have them. The good ol government just set the date back when all cars must have them so im not quite sure when that is. The sensor will sit in the wheel rim and measure pressure, temperature, and speed and will send signals to the car.