Sub-Throttle Position (Sub-TP) Sensor (With TRAC)
WARNING: This page is about a different car, the 1997 Lexus SC 300. However, it is still accessible from the selected car via links, so may be relevant.
Vehicles with Traction Control (TRAC) system are equipped with a secondary (sub) throttle plate that is controlled by an electric actuator. The ECM monitors the angle of this sub-throttle plate by applying a reference voltage to the sub-TP sensor, which operates like the TP (main) sensor. Sub-TP sensor also contains an idle switch.