Tire Pressure Monitoring System problems of the 2004 Toyota Highlander

I had a tire go very nearly flat and the low tire indicator on my 04 Toyota Highlander never illuminated. A passing motorist made me aware of the tire condition. I barely was able to make it to a station without ruining the almost new tire. I had just came into town, and was previously at highway speed with 2 elderly passengers besides myself. My local Toyota dealer here in mckinney TX said that Toyota tech support says there is nothing they can do. Even though I had just driven about 5 miles to the dealership with one tire purposely under inflated by 10 pounds to prove to them that it was not working, they are telling me that Toyota will do nothing about it, except to verify that there is no codes set in the computer!.

Indicator lights on dash say contact your dealer. One is the tire pressure and the other is the engine. Have carried to dealer 3 times and still occurs. They are supposed to pickup tomorrow and correct tire pressure light. Only listed last date.