Circuit Description
WARNING: This page is about a different car, the 2003 Lexus IS 300. 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, magnetic clutch, TP sensor, accelerator pedal position sensor, ECM and throttle body. ECM controls throttle motor to adjust throttle valve opening angle. DTC P0505 is set if idle speed continues to vary greatly from target speed (2 trip detection logic). Possible causes are:
- Faulty Air Induction System
- Faulty ETCS.
- Faulty ETCS circuit.
- Faulty PCV piping.
- Faulty ECM.