Initializing the tire pressure warning system?

No it's not necessary. However, if you bump up your pressure to say 42/40 from the Toyota recommended pressures, then you should reset the TPMS for the new pressures.

 

I have bumped my tire pressures from the factory. Is there a simple way to reset the TPMS to the new pressure? I didn't seen anything about this in the manual.

 

Thank you SO much for this thread! Never had a tire warning system before, so never gave this a thought. I had to put air in my tires == my MPG dropped from a consistent 48.8 to 47.2. Discovered the pressure in each and every tire was way down, due to the cold temps. So I put air in, and went to the "new" 42/40. Will attend to the reset tomorrow (day light). Thanks so much!

 

The reset essentially tells the system, "The pressure now is the correct pressure." If you want to run the tires at a different target pressure, that's when you reset the system. If a tire is low but you're refilling it to the same pressure as before, you don't need to reset anything.

 

One thing that is not clear, and the dealer also isn't clear about this is, at what pressure does the dash indicator warning light come on. One says at 25% below the set point; another said at the factory pressure on the door jamb (32/30).
I tried a test and it seems to be at 32PSI which was 25% below the set point. I had set the pressure to 40PSI for some testing. BTW, I don't notice any difference in mpg from tire pressure. From the various driving situations: hell yes!

 

The system will trigger once ANY tire pressure drops to 75% of its set point. Put all tires to 40 PSI and set system, if any tire hits 30 PSI, you will get a signal. If you have front = 42, rear = 40; IF front drops to 31.5 OR rear drops to 30, the alarm will trigger.