Check the throttle body
Some Ford vehicles may exhibit DTCs P0505, P0506 and/or engine idle rpm fluctuation and hard starts. These vehicles may also exhibit DTCs P2111 and P2112 after the KAM has been cleared, or if the battery has been disconnected or if the battery is dead.
On vehicles with over 10,000 miles, the issue may be caused by sludge buildup in the electronic throttle body, reducing airflow. Affected vehicles include 2005-2008 Crown Victoria, 2005-2009 Mustang, 2004-2006 F-150, 2004-2007 Explorer and F-Super Duty, 2005-2006 E-Series, 2006 F-53 Motorhome Chassis and 2007 Explorer Sport Trac.
1. Using IDS datalogger or equivalent, check the PID value of ETC_Trim. If ETC_Trim PID is not available, go to Step 2. If available, go to Step 3.
2. Reprogram the PCM to the latest calibration using IDS release 75.03A or higher.
3. With the vehicle in park or neutral and with the A/C off, start the engine and allow it to reach normal operating temperature which is greater than 170 degrees Fahrenheit.
4. While the engine is running, using IDS datalogger or equivalent, check the PID value of ETC_Trim. If ETC_Trim value is 3.0 degrees or greater, proceed to Step 5. If ETC _Trim value is less than 3.0 degrees, but drivability concerns persist, refer to Powertrain Control/Emissions Diagnosis in the service manual for normal diagnosis.
5. Remove the throttle body and using Motorcraft Choke and Linkage Cleaner or equivalent, spray the throttle body plate and bore. Using a small, soft solvent-resistant brush, clean the edges of the throttle body plate and the mating surface of the throttle body bore to remove any engine deposit buildup. Re-apply the spray cleaner. Do not spray cleaner directly into the throttle body plate pivot shaft. Reinstall the throttle body.