If the engine idle speed drops lower than 750 RPM, the PCM will store
the P0506 diagnostic trouble code.
When
the P0506 diagnostic trouble code is stored by the Powertrain Control Module (PCM), it is an indication that the revolutions per minute (RPM) of the idle control system is lower than expected.
Common causes of
the P0506 diagnostic trouble code are vacuum leaks and dirty throttle body air passages.