Circuit Description

WARNING: This page is about a different car, the 2003 Lexus GX 470. However, it is still accessible from the selected car via links, so may be relevant.

Electric Throttle Control System (ETCS) is composed of throttle motor to operate throttle valve, throttle position sensor to detect opening angle of throttle valve, accelerator pedal position sensor to detect accelerator pedal position, ECM to control ETCS, and one valve type throttle body. ECM controls throttle motor to make throttle valve opening angle correct in response to driving condition. Throttle position sensor, which is mounted on throttle body, detects opening angle of throttle valve, and provides feedback to ECM to control throttle motor. If ETGS has a malfunction, ECM shuts down power for throttle motor and throttle valve is fully closed by return spring. Also, all electronically controlled throttle operation is cancelled until system returns to normal and ignition switch is turned off. DTC will set when throttle opening angle continues to vary greatly from target throttle opening angle. Possible causes are:

Faulty electric throttle control system.
Defective ECM.