Circuit Description

WARNING: This page is about a different car, the 2003 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.

Throttle Position (TP) sensor uses 2 sensors which detect throttle opening and a malfunction of the TP sensor. TP sensor is located on throttle body and provides an input voltage of 0-5 volts to VTA1 and VTA2 terminals at ECM in proportion to throttle opening. ECM uses input signals and controls the throttle control motor to provide proper throttle valve opening in response to driving conditions. DTC is set when improper input signals from TP sensor are received at ECM. If DTC(s) exist, the throttle valve is fully closed by the return spring and throttle valve is locked at a certain opening angle. Also when this occurs, the whole electronically controlled throttle operation is cancelled until the system returns to normal and ignition switch is turned off. Possible causes are:

TP sensor circuit is open or shorted.
Defective TP sensor.
Defective ECM.