Fix code P1506 Ford high idle speed
If you own a Ford Escort, Focus, or Tracer with the 2.0-liter engine and experience a high idle speed or trouble code P1506. The official definition is P1506 Idle Air Control System Over speed Error. That means the idle air controller has tried to maintain the proper idle speed, yet the idle speed is still too high.
Start by disconnecting the connector to the idle air controller (IAC) solenoid. The idle speed should drop very low. Or the engine may stall. However, if the engine still idles normally (or high), check for a vacuum leak or a bad PCV valve. Even if you’ve replaced the PCV valve recently, double check to make sure it’s the right one. Installing an incorrect PCV valve can allow too much airflow at idle, forcing the RPMS up past the point where the IAC can compensate.
© 2012 Rick Muscoplat