Replacing TPMS Sensors

[steppinthrax]

I have a 2006 toyota sienna. I found recently that the previous owner removed all the tpms sensors???? I had a flat tire and upon inspecting the tire, there was just a simple valve stem. The minivan has tpms. There is a button on the knee bolster. If I hold it the tire light will illuminate three times (when the key is in the ON position). So my question is.

1. If the sensors are missing shouldn't the system indicate a constant tire light?

2. What frequency sensors should I get?

3. Why did the previous asshole remove these, they are expensive?

[Billiam]

I could be wrong, but I thought the Sienna went to individual senors in '07. The '04-'06 used an ABS based system to measure any rotational speed difference in the tires caused by underinflation. The ABS based system does not use sensors.

[steppinthrax]

Originally Posted by Billiam

I could be wrong, but I thought the Sienna went to individual senors in '07. The '04-'06 used an ABS based system to measure any rotational speed difference in the tires caused by underinflation. The ABS based system does not use sensors.

I believe you may be right, after creating this thread, I was reading that only 07 and up have individuals sensors. So the question is now, why didnt' my light go on while pulling out of the parking space while driving on a RIM!!!!

[Billiam]

It depends on how far and how fast you went. I think the ABS system has to read a rotational difference above a certain speed in a relatively straight line for a certain period of time.

Remember that this type of system can't actually tell you that you have no air in a tire. I suspect if you had been willing to drive fast enough for a few hundred yards the light would have come on.

[warren4066]

^ you are right, you have to drive it for awhile til the low air pressure indicator comes on. mine does this all the time. i just deal with it as long its not flat