Limp Mode?
 

I just had the fuel control module replaced on my 6.0 and the limp mode warning is comming on durring longer drives. There is no loss of power and this is a new truck to me, does anyone have any ideas? When the truck is shut off it doesn't come on till the next drive.

Moved to the 6.0L Powerstroke Diesel forum.

If it just started doing this since the work was done take it back.otherwise id monitor your oil temp and coolant temps to see what the sptead is between the two.you will get a wrench light if they get to far apart for to long.

When the FICM was replaced your truck got the latest flash that includes the enhanced warning software to let you know more things are going on with your motor. The wrench light will "reset" when the PCM detects that whatever's out of whack is back within spec. As steelhead said, you need to monitor the motor parameters to see what's going on. My best guess would be that your engine coolant and oil coolant temperatures are a lot further apart than they're supposed to be after the truck gets to operating temperature but without true gauges there's no way to know for sure.

FWIW--the gauges on a 6.0 are virtually worthless. The oil "pressure" gauge, coolant temp gauge, and trans. temp gauge are not much more than idiot lights with needles. The boost gauge, tach, and speedo are good. You need to get something to monitor your engine parameters. I use a ScanGaugeII that's very basic but gives a TON of information. It reads virtually everything the PCM reads except fuel pressure and exhaust gas temperature because there are no sensors for those. I HIGHLY recommend you add a fuel pressure gauge and, if you tow regularly, an EGT gauge.

If the wrench light was on, there should be a code set. If you can get the code read you will have a much better idea of exactly what is wrong.

I didn't think the wrench light set codes.......at least I've never been able to read them with anything I have.

I might be wrong but that's what I think I remember reading.

Having an '04 with no wrench light at all, I couldn't say for sure.

they do and you cant :)

Thanks David and Moe. Something to add to my "learned something new today" book about the 6.0, which, btw, is getting pretty thick now.

Bringing up this old post because my wrench light came on this past weekend, and the truck went into limp mode. I was able to read the code though with my Insight. It was showing a P0234, which is some kind of overboost condition.

I was towing my 9500lb travel trailer when it happened. I was holding between 60 and 65 and was driving up a long gradual hill (not steep by any means, but it was uphill for as far as the eye could see) and I had about a 20mph headwind. We were almost to our lunch destination, so I limped it in there and let her rest while we ate. I cleared the codes and didn't have any other problems on the way home, but I kept a pretty close eye on it and tried not to let the boost up near the top (when it hit 28psi after a gear shift, I let off and dropped it down).

Anyhow, what is my next move here? Should I just keep going and see if/when it happens again? I'm out of warranty and don't want to have to take her into the dealer right now (leaking slab to fix first).

keep an eye on the boost levels. more then likly turbo is starting to stick.

Thanks cheezit. I'll keep an eye on things and try and stay out of the pedal for now, especially when pulling a trailer. My Insight tracks certain parameters, and it did show that my max boost was 29psi, so I assume that this is what caused the truck to go into limp mode.

So I guess the next time it happens it will be time to do something about this? I read on this post or a different one that it only takes you about an hour to remove, clean, and re-install the turbo. What is the book time (what will the dealer charge roughly)? I need/want to get my brake and steering system flushed sometime soon, so I may let them mess with the turbo while it is in there, depending on the cost.

warranty pays 3hours not counting diag. expect to pay between 4-7 hours depending on how they charge.

Good to know. Thanks for the info.

One more question - how do I keep this from happening again in the future? The first week I got the truck, the check engine light came on with the same overboost code. It was covered by warranty, and they just pulled the turbo and cleaned it. That was two and a half years ago.

This time, the wrench light came one (not sure why it wasn't the check engine light). Should I expect to have to pull the turbo and clean it every couple of years?

FYI, my truck sits for one or two weeks at a time, but gets driven on the highway when I do use it (usually at least 100 miles at a time). Half of that time, it has a trailer on the back (anywhere between 3500 and 9500lbs), so it does get a work out. When the truck is empty, I try and goose it every once in a while to keep the turbo 'worked out,' but apparently I need to do something else. My daily commute is only a mile, which is why I don't drive the Ford every day... I figure that it's better for it to sit for a week or two instead of being driven such short distances all the time.

sadly its just pretty much one of those things.