Any tC owners experiancing a false tire pressure sensor warning?

After driving for 20miles the sensor triggers and I get the { ! } warning on my dash. I reset it the next time I'm at a stop and it will do it again in another 20 miles. I've checked my PSI on all the tires and they are fine.

 

I'm not sure if its the same thing, but my dad's 2002 Sienna does the same thing... sensor comes on but PSI's are all fine

He thinks he's got it figured out to where after you drive for a while, especially in the sun, the air in your tires will expand enough to where it triggers the warning. He says he can make it go away by resting somewhere for a bit, resetting the sensor, and then as you say it'll come back after a certain period of time.

I figured they would've adjusted the sensors for that stuff by now...

 

Well 10k miles is coming up in about 2 weeks so Stevenson Toyota will be looking into it... I don't have a warranty for nothing!

 

is he setting the pressure in the spare tire??
on the newer model toyotas the spare tire has to be set with the rest of the tires for the light to go off, but i have seen cases of this happening on older model siennas

 

i am having that problem in my tc. i have reset it many times. the tire pressure is find, i don't know what to do about it.

 

Heres what you do if you havent figured it out yet. You turn the car on, but not started... hold the reset button until the light goes out. then let go of the button, wait a second and press and hold the button again, hold it until the pressure sensor light on the dash blinks 3 times. as soon as it blinks for the 3rd time, let go of the reset switch.... TADA!! I had the same problem, pressure light was on for about 3 months after cracking a pothole pretty bad.then i found this out

 

is he setting the pressure in the spare tire??
on the newer model toyotas the spare tire has to be set with the rest of the tires for the light to go off, but i have seen cases of this happening on older model siennas[/quote]


the sensors in the scoin are not the same as in most toyotas, they use a signal to measure the out of balance of the tire. you do not have to set the spare because they are not built into the tire, and they are not full size spares only the full size spares have to be set. on the tires with sensors a 6 p.s.i. difference in the tire either way is what activates them initially and a 4-6 psi difference after that depending what the ECU determines. as for this guy, sounds like a faulty sensor, do you live in a bumpy area??