Circuit Description

Idle Air Control (IAC) valve is a rotary solenoid type and is located in front of air intake chamber. Intake air by-passing the throttle valve is directed to IAC valve through a passage. This allows air volume by-passing the throttle valve to be regulated. DTC P0505 is set if idle speed continues to vary greatly from target speed. Possible causes are:

• IAC valve stuck or closed.
• Open or short in IAC valve circuit.
• Open or short in A/C signal circuit.
• Faulty air intake hose.
• Faulty ECM.