Circuit Description

WARNING: This page is about a different car, the 2002 Toyota Sequoia. 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 uses throttle control motor to operate throttle valve opening angle to obtain target idle speed. DTC is set when idle speed continues to vary greatly from target speed. Possible causes are:

Defective ETCS.
Air induction system malfunction.
Defective Positive Crankcase Ventilation (PCV) valve piping.