I have a '04 F150 SCrew Lariat 4X4 with about 8400 miles on it. This morning I started the truck, pulled out of my driveway and got about 100 feet down the street when "engine is in failsafe mode" popped on in the message center. I turned around and pulled back into my driveway, and turned off the engine. After a few seconds I started the truck again and everything was normal. and I had no problems driving to work (about 20 miles). The only info I can find is that this is supposed to happen if the engine overheats. It was about 50 degrees outside (california winter weather) and the engine hadn't even had a chance to warm up (temp gage was still below the "C"). Has anyone had this happen to them, and found out what could have caused it? I'm trying to find out anything about this before I end up having to take it to the dealer.

 

dealer replaced my throttle position sensor after the second time it occurred, first time they flashed the computer with the update. worked fine for about a week and same problem again. with the tps replaced i've had no problems with the engine since. if i recall i think my light turned off after i restarted it, mine came on just shifting into reverse both times.

 

failsafe mode will happen whenever the computer senses a sensor out of tolerance.
There is probably a code stored, I would have them check it out. Probably just a laze o2 sensor,
MK

 

the sensor was bad, i.e. inoperative. and there have been other people with the throttle position sensor issues, hopefully there won't be one starting with the o2 sensors now

 

Just take it to the dealer and they'll know how to fix it. There has been plenty of this problem going around. Mine did it and I took it in and they replaced the throttle body and re-flashed my module and I haven't had any problems since.

 

I took the truck to the dealer and the tech told me that ford doesnt have a bulletin on this problem, but they did state that this is a "rare anomaly" (after I mentioned the throttle sensor) and they ordered a new sensor to install.

 

Dealer replaced TSP and continue to have problem of engine failsafe mode initiating on the road. Any secondary fixes to be aware of?

Also, anyone else have engine failsafe mode bad experiences? The failsafe seems very dangerous as the whole vehicle shuts down sometimes and that includes power steering. Re-engaging the engine also requires turning key off, which temporarily disengages power steering.

 

Either a bad flash in the PCM or a bad PCM or a bad TPS.

 

Holy thread revival Batman! Back from the dead after more than 5 years!

Great use of the search feature cmc!

 

my truck went into fail asfe during the test drive.

it stalled at a stop light, then after i restarted it went into failsafe.

dealer installed a new throttle body. been great ever since.

 

No kidding! The post I made a few before this one was 12/10/2004! I haven't even owned that F150 truck for a few years now! hahaha

 

Wow...what else might we find in the time capsule? Yes it was a magical, simpler time when little was known about global warming and even less was known of the dreaded spark plug issue.

My Edge would sometimes send my rig into failsafe on level 3. Had to do with PCM interpreting MAF sensor readings from my Volant and the programmer not remembering my wheel diameter and gear ratio. Wasn't that bad, just a loss in thrust until I could safely pull over and set everything back to stock.

 

Thanks, the dealer has suggested the same and having it replaced today.

 

My 2005 F150 (5.4 triton) went into "engine fail-safe mode" when I started it in my garage. I turned the vehicle off, restarted it and all was normal. I read all the threads on this forum and decided to have the dealer clean the throttle body and check for codes. No codes and it hasn't happened again in a week. The day before the fail-safe mode display, the truck was running a bit strange…almost as if on fewer cylinders with reduced power. Perhaps this WAS fail-safe mode without the display being activated. At this point all I can do is monitor and hope it doesn't happen again. Does anyone on this forum have any ideas or "next-steps" for me to try? I'm almost afraid to take any long trips with the truck for fear of having to limp home. Thanks in advance for your replies.

 

About a year ago or so I experienced the "fail safe" mode. This was coming off a long interstate run and slowing down for the city. Doing some research I decided to clean the Throttle body. Which was somewhat dirty. The incident has not reoccurred. I would suggest this first generation vehicle is a finicky devil, and has cost me some coin. Running good currently.