steve181

In a few months your tire pressure warning light will come on and you can play 5 way roulette to find the low tire. My son has an 07 RX-350, my wife an 08 RX-350. Both have the same annoying problem. I suppose that any car with a TPMS would have this, but on a $40 - 50 K car I would expect it to tell you which tire is low - especially with such a sensitive TPMS. Steve

Every few months the tire pressure warning light comes on in our 2008 RX-350. Its then a wild goose chase through 5 tires to find the one that is low. (FYI - My wife can not believe that an expensive car like this does not tell you which is the problem tire!) It would seem easy to design a small hand held scanner that you could hold next to the valves one at a time to interrogate them as to which is signalling low. Does anyone make such a gadget? It would sure save a lot of time. Steve

I had the same problem. I spent some time with the manual and on web blogs. I got the problem fixed and the light is now out! Here is the definitive info: 1 - The tire pressure monitoring system does monitor the spare. This was the cause of my problem. 2 - Although the spare is mounted under the car, with the valve facing up, you can get at that valve by using the screw jack elevator system that is in the manual. You don't have to remove the spare, only lower it enough to reach the valve which is mounted facing UP. That was easier than I thought, once I had carefully read the manual and found all the buttons and things to use. 3 - After everything is done you have to reset the system by using the button under the dash, to the right of the wheel. You have to be careful to use the correct button (the left one) so as not to disable the anti-skid system. All in all the system is not bad, but Lexus should do a much better job in its manual explaining things. This could happen several times per year. I guess they want to have their service Dept. make money.