Some 2006 Ford F-150 and Lincoln Mark LT pickups with 4.6- or 5.4-liter engines may produce a higher-than-normal idle speed. On vehicles with 5.4-liter engines only, the owner may also complain of an intermittent hard start condition.
According to Ford Motor Co., the check engine light probably will turn on when either drivability issue occurs, with trouble code P0606 storing in computer memory.
Software gremlins in the PCM are a likely cause for all the trouble, said the car maker.
To make a definitive diagnosis, clear the trouble code, restart the engine and run a KOER test. If the code resets, this information doesn't apply; continue with normal troubleshooting until the cause is revealed.
If the code clears and doesn't reset or the idle or starting troubles resurface, that's your cue that the PCM needs updated software. Check with a dealer for the specifics of the flash.
"Factory Fixes" is written by Jim DePalma, a 30-year veteran of the auto repair business who has served stints as a service manager, parts manager and ASE-certified technician. His column provides vehicle manufacturers' authentic factory technical service bulletins (TSBs) that have been condensed for easier reading. Mr. DePalma advises that techs always check with a dealer or repair information system for the latest revisions before starting to work on a vehicle. He can be reached via email at [email protected].