Ford P0508 OBD-II Trouble Code Definition:
P0508 Idle Air Control Valve Sense Circuit Low
P0508 Ford OBD-II Trouble CodeDescription:
OBD Trouble Code P0508
Idle Air Control System Circuit Low
What does the code mean? OBD-ii Code P0508 definition:
The ECM controls the engine idle speed to a specified level through the fine adjustment of the air, which is let into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve is varied to allow for optimum control of the engine idling speed. The ECM calculates the actual engine speed from signals of crankshaft position sensor (POS) and camshaft position sensor. The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value memorized in the ECM. The target engine speed is the lowest speed at which the engine can operate steadily. The optimum value stored in the ECM is determined by taking into consideration various engine conditions, such as during warming up, deceleration, and engine load (air conditioner, power steering and cooling fan operation, etc.)
The ECM controls the engine idle speed to a specified level through the fine adjustment of the air, which is let into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve is varied to allow for optimum control of the engine idling speed. The ECM calculates the actual engine speed from signals of crankshaft position sensor (POS) and camshaft position sensor. The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value memorized in the ECM. The target engine speed is the lowest speed at which the engine can operate steadily. The optimum value stored in the ECM is determined by taking into consideration various engine conditions, such as during warming up, deceleration, and engine load (air conditioner, power steering and cooling fan operation, etc.)
Symptoms Sumptoms of OBD code P0508
– Engine Light ON (or Service Engine Soon Warning Light) – Engine hard to start – Rough or erratic idle speed
– Engine Light ON (or Service Engine Soon Warning Light) – Engine hard to start – Rough or erratic idle speed
Causes Causes of the OBD-II code P0508
– Dirty throttle body – Electric throttle control actuator misadjusted or damaged – Faulty Electric throttle control actuator – Intake air leak – Poor electrical connection to the Intake Air Control (IAC) valve
– Dirty throttle body – Electric throttle control actuator misadjusted or damaged – Faulty Electric throttle control actuator – Intake air leak – Poor electrical connection to the Intake Air Control (IAC) valve
Solutions If there are no intake leaks, clean throttle body, adjust engine idle and erase engine code. If the code comes back you may have to replaced the Electric Throttle Control Actuator (Motor) to repair the problem.