OBD Code P0509

Idle Air Control System Circuit High

What’s mean?

OBD2 Code P0509 Definition:
The ECM has detected that the IAC counts are higher or lower than expected, the engine speed is not in its expected range.

Symptoms

Possible sumptoms of P0509
– Engine Light ON (or Service Engine Soon Warning Light) – Engine hard to start – Rough or erratic idle speed

Possible Causes

Possible causes of P0509
– 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

Possible 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.