Last night the TPMS light came on on my month old 2010 Prius. I checked all the tire pressures and they we @ 38 rear and 40 front. TPMS light went off after 4-5 times of turning the car on/off. What might have been the problem? Is it something I need to be concerned about? Anyone had this issue on their new 2010?
Have you tried the reset/set button under the dash? Read about it in the Owner's guide. Since those pressures are higher than normal, you might want to set the monitor.
I will try doing that, but the tires have been on these pressure for almost 20-30 days now. Any reason why the light came on now?
How do I see the tire pressure? Does the dashboard tell you the pressure of each tire? Which button do I press? (I'm at work and do not have access to the dashboard or manual)
Change in temps could move the pressure of a tire outside of the range and set off the sensor. I think someone mention +/- 5psi range before the light goes off. Just a guess though.
On my HyHi, the spare tire (full size) also has a TPMS sensor. I'm not certain about the Prius G3 (donut) I don't have my manual handy since I'm at work - but it might be worth checking.
You use a special tool called a tire pressure gauge, which can be purchased at any auto parts store. (Sorry, I couldn't resist, but that is the only way to get your tire pressure readings on a Prius.) Tom
Check out my thread: http://priuschat.com/forums/gen-iii...-tire-pressure-warning-light-dead-sensor.html I finally figured out what my problem was - messed up TPMS ECU (computer). Once I got that replaced (for free) all was well. Read over that thread. You may find some of it valuable information.