2005 Expedition: check engine / rough idle - Ford Forums

billyrb · 08-04-2009, 08:30

We have a 2005 Expedition with the 5.4L. Recently the battery died and we installed a new one. Immediately when we started it up for the first time after changing batteries, the check engine light was on and it idles rough. Autozone gave a code 506, Idle Air control, but from what I've found, this model doesn't have that (throttle by wire). Does anyone have any idea of whta might be wrong? Also, is there a place where various codes are listed?

**360ci** · 08-13-2009, 20:20

I would think that throttle-by-wire would not have a throttle position sensor in the TB as it'll be electronically controlled, but the throttle shouldn't have anything to do with how the engine idles... I could be wrong but there should be an IAC somewhere as the truck still idles with your foot of the accelerator pedal.