Ok I read all the threads I could find on this before and after my tire change. I had 4 265/70/17 Revo's installed by Wheel Works. I specifically told them not to touch the stems because of the tire pressure monitoring system. When I got the truck back we set all 5 tires to 36psi. The light came on and has been on ever since.

One Dealer told me to bring it in and they will reset the system. I want to go back to Wheel Works and have them fix it, taking it around the corner to Toyota if need be. I do not understand why the light is on if they did not touch the stems, the tires are on the stock wheels and all 5 have the same pressure, to the pound. Thoughts?

I thought I remembered reading something about keeping the rims (or stems) in range of the vehicle during tire changes. If the system misses one stem reading (which would happen if the rim/stem was taken more than 10-12 feet away from the vehicle) for more than a few seconds it needs to have the stem re-registered to the system.... I'll keep looking, but something like this is probably the culprit. Even though all stems are responding, the system needs to register the stems to your vehicle again to identify them to your vehicle (just think what the system would do if you parked next to another 4runner with the same stems).

I agree that it has been difficult to get an accurate description of how the TPMS works. I just spoke with Toyota, 1-800-331-4331, and they told me it is a direct sensor system. The sensors respond to the echoing of rubber?

I guess they mean that when the air pressure is different the echoing is different within the tire. Not very helpful.

I should think that since you went to a specialty tire place that they would do the follow-up to get it working. Absent that, you might have to go to the dealership so that they can do a diagnostic - because they will know how it works.

The good news is that regardless of the tire size the sensors should work. My specialty tire place put my revos on and luckily I did not get a warning light.

How about a pic of your truck? I'd like to see the lift!

Had my REVO install a couple of weeks ago and my TPWL did not come on. I think when the shop install your new tires they did not turn the key all the way off and the power was still on (but motor not running) so that why the light came on cause the system was still active and running.

I had a flat and so the tire pressure light went on. A week later I left this wheel at the shop to have the flat patched and several hours later went back to pick it up; once I had all five wheels inflated and back on the truck the tire pressure light went off seconds after I started the engine.