Engine code p1509
Asked by ELITE_2210 Mar 06, 2017 at 01:22 AM about the 2000 Ford Expedition
Question type: Maintenance & Repair
Check engine
1 Answer
P1509 - Idle Air Control Valve System High RPM...Possible causes; Faulty Idle Air Control Valve, Idle Air Control Valve harness is open or shorted, Idle Air Control Valve circuit poor electrical connection...The target idle speed is in the Engine Control Module (ECM) memory for various engine conditions (coolant temperature, A/C operation and so on). The ECM keeps the actual idle speed at the target idle speed by switching the Idle Air Control Valve IACV) ON/OFF to control the intake airflow. If the IACV output duty cycle (the length of ON time) is out of a specified range, a malfunction is detected and a DTC is stored.