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.
Idle speed is controlled by Electronic Throttle Control System (ETCS). 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 for target idle speed. DTC is set when idle speed continues to vary greatly from target speed. Possible causes are:
- Faulty air induction system.
- Defective electric throttle control system.
- Faulty PCV piping.