DTC P0506: Idle Air Control System Rpm Lower Than Expected

WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

P0506 - IDLE AIR CONTROL SYSTEM RPM LOWER THAN EXPECTED

Description:	This DTC is set when the PCM detects actual engine speed that is lower than the desired RPM.
Possible Causes:	Air intake restriction. Exhaust restriction. Engine mechanical fault.
Diagnostic Aids:	This DTC is informational only and it may be accompanied by other DTCs. Diagnose other DTCs first. If other DTCs are not present, inspect the entire air intake system for restrictions. Repair as necessary. If no restrictions are found, clear the DTCs.
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
All	This DTC is informational only and it may be accompanied by other DTCs. Diagnose other DTCs first. If other DTCs are not present, inspect the entire air intake system for restrictions. Repair as necessary. If no restrictions are found, clear the DTCs.