DTC P0505: Idle Control System Malfunction: Condition

DTC is set when closed signal to Idle Air Control (IAC) is not detected with engine running. ECM continuously monitors this circuit. MIL is illuminated when Engine Control Module (ECM) detects malfunction during 2 consecutive drive cycles. Possible causes are:

• Short or open circuit between main relay, IAC valve and ECM.
• IAC valve malfunction.
• ECM malfunction.