P0500 0205 Idle Air Control Valve Nissan Trouble OBDII Code Diagnosis Fix

P0505 Idle Air Valve (IACV) - Auxiliary Air Controlv (AAC) Valve

Then system automaticaly controls engine idle speed to a specified leve. Idle speed is controlled through fine adjustment fo the amount o fair which by-passes the throtle valve via IACV-AAC valve. The IACV-AAC valve repeat ON/OFF opeation according to the signal send from the ECM(computer). The camshaft postion sensor detects the actual egnine speed and sends a signal to the ECM. The ECM then controls the ON/OFF time of the IACV-AAC valve so that engine speed coincides with the target value memorized in ECM. The target egine sped is fthe lowest speed at whcih the engine can operate steadily. The optimum value stored in teh ECM is determined by taking into considation various engine conditions, such as during warm up. decelartion and engine load