I was on my way back to school like I have for the last 3 years but this time I had my TPMS sensors which were taken off my truck in early '05 because of my new wheels already had balanced tires on them. I had them in a plastic baggy in the center cup holder and as usual about 30 min in to the drive the warning TPMS light comes on without the long beep. I had them because I am getting new tires tomorrow so I am going to put them back on. Then about 30 min later The 10 second beep goes off but the light had been on for at least 30 min prior. It has not beeped since I took them out. Always a light but no beep. But now the light is on all the time even with them removed from the cup holder even if I let it sit overnight and start it next morning it is still on. So I do not know because they have not been programed and are not in the wheels. It is probably nothing but I thought I would share and see if anybody else has had a similar experience.

These tire pressure monitors things have a mind of their own.
Im using my spare currently that has no sensor.
Sometimes the light will go out and if i check the pressure on the screen on the dash it gives me a figure!

Not a correct figure, as it usually reads 27 yet the tire is fully inflated so should say 35-37.

How can it know with no sensor!!

When the sensors are in the vehicle with no pressure on them the system is trying to figure out what is wrong, that is why you got light then later the alarm.

With the sensors not in the vehicle it is the same as having tires with no sensors and the light will stay on until they are replaced.