I have a 2005 F150 Lariat and live in Colorado, so driving the mountains is critical. Going up any hill, when engine is under power the engine noses over and will barely run (20 MPH) and the engine light flashes then it will start to build RPM and gain power back until 3000-3500 rpm and the it starts all over. Change plugs (UGH) done. Clean throttle body. Done. New coil /plug boots...done.. 4x4 vacuum solenoids, done. Transfer case actuator motor, done.. Vacuum pull down test, done.. Today the transmission went out and left me walking again. Dealer is Phil Long Ford who wants $300 to diagnose computer and running problem and estimate to fix starts at $2000 and could be as high as $7000... now transmission will be $2500 .. Really!!! What is Fords better idea???

Was driving down the highway at 65 mph when I looked down to notice the engine fail safe message flashing in the tachometer. Engine power was virtually non existent at this point. So here I am in tons of traffic with an 8000lb lead brick that I can barely steer off to the side of the road. I popped the hood to look inside the engine bay to see if anything had jarred loose or for any bad connections. Couldn't find one. So next I looked up the problem in my owners manual. It defines engine fail safe mode as, and this is straight from the owners manual.

"If the engine reaches a preset over-temperature condition, the engine will automatically switch to alternating cylinder operation. Each disabled cylinder acts as an air pump and cools the engine."

So I checked all my temperatures and this is what I got. Coolant 180 Degrees F, normal operating temp is 160-200 F Transmission 200 Degrees F, normal operating temp is 150-200 F Oil is 200 Degrees F, normal operating temp 180- 210 F

So everything checks out with normal operating temperatures, and this sh*t happens. Can't Figure out what caused it, 5000 miles ago, all plugs and fluids were replaced, All O2 sensors, MAF sensor, cleaned throttle body, Cleaned intake.

I limped it home on limited power, parked it and haven't touched it since.

This is a serious problem that needs to be fixed, because Ford knows about it and is too goddamn lazy to fix it.

2005 f150 fx4 with the 5.4l with 71,000 miles. The truck will completely shut down while driving, I'll put it in neutral then it will restart fine, drive for about a mile let on and off the gas then it shuts down again. The wrench light comes on runs in safe mode , I get trouble code p2135 p2106- ford replaced throttle body which came with a new TPS sensor and updated to latest FORDs reflash and updated software. Needless to say leave FORD with a $1200 bill for trouble shooting and parts. Well a week later bang does it all over. Bring it back to FORD 2 hrs of more trouble shooting and then FORD says they believe its my PCM/ECU- truck computer is fried. Now $300 in labor and $800 for new computer. FORDS said it was fixed, well again a week later same sh*t all over. I have no clue what to do or who to go to, to fix this problem. Now i want to get rid of this truck. I cant sell privately cause the next person who owns the truck will get into a major accident, I can't trade it in and lose a ton of money. Oh also had FORDS broken spark plug problem too.

I owned my 2005 Lariat 4x4 CC from new. Never had a problem until last year. The mileage was about 65000 when the Engine Failure Code appeared and the engine shut down. I replaced the mass air sensor and the TPS (throttle position sensor) and the problem was still there. I finally desided to change the throttle body myself but the replacement I was given was the wrong part. Because I needed the vehicle I had to put the original throttle body back on. I replaced the gasket and cleaned the original throttle body with carb cleaner. It was coated with a varnish like buildup under the butterfly. The problem went away now for the last 4 months. I don't know if this is the permenant fix but it will save you the $500 the shop will charge to replace the throttle body.....Good luck.

well For the past couple of months my truck has been going into engine failsafe mode but no codes comes up. So I take it to the dealer and they tell me there isn't anything they can do since it isn't giving them codes. Finally it goes into failsafe mode and a code comes up. Its the throttle body so I have the throttle body replaced. Then another code comes up and says that I have a misfire in cylinder #1 and 3 We go to take the spark plugs out and they BREAK!! Then I take it to have it flashed and the dealer gives me problems and then they tell me the throttle body wasn't the right one!! I dont know what to do

I have 3 problems with my truck. It is currently in the shop with the dealer. I had it go into fail safe mode twice and the dealer suggests that it is the throttle body going out. Came back to be number 8 coil had it replace and it did again. So I took it in friday 6/4/2010 to have tune up throttle body and injection service and wheel alignment. Mind you I work for ford motor. They have broken 3 plugs thus far, and still are not finished with my vehicle. They informed me that they were charging me $98 per plug that broke. Mind you they had not finished taking them all out.

As a Ford employee I am so disgusted. It hurts to say that I will never purchase a vehicle again from the company in which I work. This estimated bill is at $1000 and counting!!