My check system light came on but my tire symbol is flashing at me also. What does that mean? And what is the TPMS? I drive a 06 GS300 that I've had since Feb.

 

how do you reset the tire pressure using the reset button under the driver dash ?

 

You just hold it until the Initialization message comes on on the screen, then you wait 20 minutes in park for the message to disappear. Of course you have to have 4 working TPMSs. Resetting the system won't make the message disappear if a sensor went bad.

Check system + flashing tire pressure symbol mean all 4 sensors are bad. When only part of the sensors were, I just had the Low tire message.

 

I totally agree that 2006 GS300 gas cap is a crap.

It didn't matter how carefully and tightly I tighten the thing, I keep getting CEL P0455 / P0457.
When I examine the cap, it looks just fine, but obliviously it was not
because after I replaced it with the after-market cap from O'Reilly's for $18-20
the problem has not appeared for nearly a year now.

I made a video on this.

 

I had a tire pressure system flashing on my gs300 2006, turned out i had 2 bad sensors. I bought four tpms sensors from amazon for 60cad and had them installed. I then bought obd wire and techstream cd to relearn tpms myself. I typed in codes into data techstream and all 4 were paired and show live data of psi and temp. However when i start driving every once in a while the check system light with ! will come on for random amount of time and then stop. Sometimes it happens 3 times in a 10min drive, sometimes it wont come on for hour. It should be noted that i did also dent my rim inbetween changing tpms so im not sure if thats something to do with it.