Troubleshooting
DTC P0505 IDLE CONTROL SYSTEM MALFUNCTIONCIRCUIT DESCRIPTION
DTC Detecting condition:
The rotary solenoid type IAC valve is located in front of the intake air chamber and intake air bypassing the throttle valve is directed to the IAC valve through the passage.
In this way the intake air volume bypassing the throttle valve is regulated, controlling the engine speed.
The ECM operates the IAC valve only to perform idle-up and provide feedback for the target idling speed.
Wiring Diagram:
Step 1:
Steps 2 - 5:
Step 5 (continued) - 6:
INSPECTION PROCEDURE
HINT: Read freeze frame data using LEXUS hand-held tester or OBD II scan tool, as freeze frame data records the engine conditions when the malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.