Fix P0505, P0506, hard start, rough idle on Ford vehicles
Fix P0505, P0506, hard start, rough idle
Ford has issued a service #12-7-4 to address trouble codes P0505, P0506, hard start, rough idle on the vehicles listed below. The vehicles may also store enhanced trouble codes P2111 and P2112 after the keep alive memory has been cleared, the battery has been disconnected or the vehicle has a dead battery.
On vehicles with over 10,000 miles the problems may be caused by sludge buildup in the electronic throttle body. That causes airflow to diminish to less than the desired level.
Vehicles affected by this service bulletin
2005-2008 Crown Victoria 4.6L
2004-2006 F-150 4.6L & 5.4L
2004-2007 Explorer 4.0L, 4.6L
2004-2007 F-Super Duty 250 & 350 5.4L EFI & 5.4L 3-valve, 5.4L LPG
2005—2006 F-450 & F-550 6.8L EFI
2005-2006 E-Series 5.4L & 6.8L
2006 F-53 Motorhome Chassis 6.8L
2007 Explorer Sport Trac 4.0L & 4.6L
2005-2008 Lincoln Town Car 4.6L
2006 Lincoln Mark LT 5.4L 3-valve
2005-2008 Grand Marquis 4.6L
2004-2007 Mercury Mountaineer 4.0L & 4.6L
Crown Victoria 2005 2008 4.6L
E-150 and E-250 2005 2006 4.6L EFI
E-150 – E-450 2005 2006 5.4L EFI
E-350 and E-450 2005 2006 6.8L EFI
Start by updating the PCM software to the latest release
Then, with the vehicle in park or neutral and AC off, start the vehicle and let it warm up to operating temperature. Attach a scan tool and check the PID value for electronic throttle body. If the ETC_TRIM value is 3.0 degrees or greater, remove the throttle body and clean it with choke cleaner.
Spray the throttle body plate and bore. Then, using a small, soft, solvent resistant brush, clean the edges of the throttle plate and the mating surface of the throttle bore to remove all engine deposit build up. Clean the mating surface of the throttle bore.