Hello. The low pressure tire light cam on. I checked the pressure and it was 28psi in all 4 tires. The label on the side of the car said it should be 30psi. I added air to all 4 tires and the tire pressure light went off. Even though the light went off i still reset the tire pressure switch (underneath the steering wheel, light blinks for 3 sec etc). Should I have not done that. Also am I correct about the tires having to be 30 psi? The guy at the tire shop said you can put more than 30. Thank you

You did the right thing. Each time you rotate the tires or have new ones installed you should reset the
sensor with the button, making the light blink three times. Doing that resets the base-line for the
sensor. If you ever have a flat (of which I have just had two) or just a reduction of pressure in one tire
which you fix, you don't have to hold the button in until you get three flashes; just hold it in until the light
goes out because you haven't changed the parameters for the sensor, you've only reset the tires to
the parameters already set.

but if you do reset it and it blinks 3 times, even though you may have only added a little air does it hurt the sensor in anyway?

no does not hurt the sensor...how can it???

Remember also, the spare is also tied into the TPMS system. Always go by the PSI on Toyota lable.

Yu are allowed to add as much as 3 PSI which is ok. Never go by the PSI on the Tire

Yep. The PSI on the tire is only the maximum amount it was designed to hold on any car. For your car, use the manufacturer recommendations.

These TPMS systems confuse many people. But I suppose they've also prevented some accidents and saved a fair amount of fuel.

32PSI is Toyota's specification (for the 19" TOYO tires)

there's a lamp on on my dash. is it about TPMS what you'r talking about?