I'll be driving my truck and all of a sudden my check engine light will come on and it will say "engine safe fail mode on" and it will start acting funny. Any idea what this could be? It just started doing it after i did an oil change. Used motorcraft 5w20 with lucas oil stabilizer. Thanks for any help.



-Matt

 

Something similar happened to me in my Expedition. I just can't remember clear enough. I took it to a mechanic that cleaned it I believe. Not sure though. One of the reasons I've planted myself on these forums is to keep myself up to date with developments and solutions.

 

Engine fail safe mode is defined in your owners manual. I'll assume you don't have one (big no no), so here's were you can download a free PDF copy:

https://www.fleet.ford.com/maintenan...ls/default.asp

It means theres a serious enough problem that causes the PCM (power train control module) to set the engine to a "limp home mode" which means minimal power; enough to get you off of the highway and to a safe location in which you can stop and shut off the engine. Don't drive it very long in this mode.

Get the codes read from the OBD II plug, located under the dash to the right of the steering column. Most tunners can read them. If you don't have one, most auto parts stores can read them (for free), but I would not drive the truck much in failsafe mode. Once you have the code(s), enter them in a Goole search window to find out what the code is reporting, possible failed part(s) that are listed as the most likely cause.

 

I have a manual but figured you guys would be better help. It needs inspected this month, so i'll set up an appointment tomorrow and have my mechanic check it out. Thanks for the help.