Hey, new to forum. Looking for some advice on my 07 lariat. So the other day it died on me, the battery was near the end so I go out and buy a new one, replace it. Turn the truck over and starts fine, 3-5 seconds later engine fail safe mode comes on and truck starts idling quite rough. Turned it off, disconnected the battery and wait a minute, reconnect, start it up and same thing. I ensured the obvious things such as positive terminal connected to positive and tried disconnecting and reconnecting. I'm just looking if someone can give me a rough idea of what it may be base on the symptoms. Rough idle, won't accelerate at all besides idiling, and check engine light and fail safe engine mode light. It blows me away how it was running like a top last week and out of nowhere it acts up on me, my only guess would be a throttle body possibly but I'm really not too sure. Ill probably wind up taking it to the dealer but if anyone has any ideas or thoughts its much appreciated! Thanks in advance.

 

The same thing happened to me after I had done a bunch of routine maintenance. I backed off the driveway, drove a few feet and got the engine failsafe warning. I pulled back onto the driveway, hooked up my scanner, and it revealed that I had neglected to reconnect a sensor on the throttle body.

It's very possible that a connector simply came loose somewhere. If nothing else, get yourself a scanner and the code will point you in the right direction. You may need to get something locally, but if you can wait to order one, I recommend the Autel AL619......works on my F150, Miata, and 350z, does SRS and ABS too. $150 or so on line.

 

Perfect thanks! Ill check for loose sensors, throttle body sensor could be possible and I may consider a scanner for what it's worth, then I can at least have an idea as to what is wrong

 

Took it to ford in Edmonton here, ended up being the PCM, which after diagnosis, parts and labour was about 2 grand. Pretty steep, sounds high for a PCM. Probably wont go back to that dealer. They showed told me which codes showed up P0122 and P0222. I know it's power train but not sure what they mean beyond that. Shop rate was 127.95/hr. any opinions on the price I paid and what the codes mean? Any help is much appreciated, it's an 07 5.4 in case I didn't mention before.

 

Well that stinks. Unfortunately, when they get us over a barrel with the mystical black arts involved in engine control computers (read: boxes we can't open up and fiddle with), there's not much we can do with it. You at least, I presume, have some warranty on the part and work.

 

Yeah that's pretty well it, not much you can do when it all computer related. But yes there is a warranty, they offer a standard one yr warranty which is ok I guess. I just hope it lasts lol. But oh well what do ya do, it's fixed and I got my truck back so I can't complain too much I suppose.