From
Brake & Front End: The Complete Undercar Service Magazine - TPMS: What a...:
"According to a Toyota technical service bulletin issued late last year, the company has
direct-type TPMSs on 11 models: the 2004-2007 4Runner; 2005-2006 Tundra; 2005-2007 Sequoia; 2006-2007 Land Cruiser, Prius, RAV4, and Tacoma; and the
2007 Avalon, Camry, Solara and
Scion tC.
In addition, Buner said that five other models use an
indirect system: the 2001-2005 Sienna, the 2004-2007 Highlander, 2004-2005 Solara and RAV4 and the
2005 Scion tC."
So that says indirect system, which means the sensing ability is embedded in the ABS system, and that in the 07 tc they went to a direct sensor in the valve stem. The article also talks about how the system has to be reset or recalibrated every time a tire comes off of the car with either type of sensor.