Hello All,
This is a fairly long post and a bit wordy.
I rarely post on this forum but have searched it a few times.
The last weekend of June it searched it heavily looking for an answer.
I never found it here nor did I find it on any other forums that dealt with the 6.7 Powerstroke.

I'll start at the beginning.
I travel to NW PA from NH on a monthly basis in the summer to shoot long range Black Powder Rifles and tow a 26ft. camper.
It's 550 miles one way.

I was down there at the end of June to run a 2 day match.
When we shoot on the 1000 yd range we close the ajacent 200 yd. range because of target setters at work.
It was 5:30 Saturday morning, I was driving down the hill to put out the closed sign.
My 2012 F350 with 115000 miles on it started binging and bonging.
The message center lit up with a low coolant level, reduced engine performance message.

I nicely asked my truck to stop doing that but it was deaf to my plea's and just barely made it back up the hill.
The coolant level was fine.

After the match I got out my $20.00 code reader and pulled a P2560 for low coolant level, which wasn't low.
I tried clearing it several times and it wouldn't clear.
Tried both keys and no dice.

I got out my bag of Home Depot tools, removed the left battery, disconnected enough stuff to lift the battery box and see if there was a level sensor under there some where.
Didn't see one.

I ran the match Sunday, buttoned up the range, packed up all the crap and tried to clear the code again.
It cleared using my spare key and I drove around a bit and thought, bullet dodged, I'll fix it when I get back to my shop in NH.
I started it again, the code returned and wouldn't clear.

One of the guys in the club runs a Jeep performance shop in town.
He came up with a good OTC Elvolve tool and we looked at some parameters and engine data, cleared the code and tried it. It came right back.
Thankfully most of the Ford guys at the club by their trucks from the dealer up in St Mary's PA.
Also some of the guys that work there are members of the club.
I figured I'd get it towed Monday and get back to NH a day or so late.

There are worse places to be stranded than a 1000yd rifle range.

I called Monday and was told a week to 10 days before they could look at it.
I explained my situation - to no avail from the service writer.
The local beer store would deliver as would the market, but I didn't bring enough ammo to stay that long.
I knew I should have brought more.

I did have internet but didn't have the log in info for the Mitchell, Identifix or Ford Tech sites we use at the shop. To make matters worse, no one there could remember exactly what they were as they save passwords for sites like those. I bought an Alldata DIY account for and read about P2560.
One of the K tests mentioned ECT sensors. I figured I could change those at the range.
The local NAPA dealer had 2 and would deliver them.
For the $28.00 cost, I changed both.

I cleared the code and it stayed cleared. Tried both keys and it stayed cleared. Drove the truck about 20 miles locally and things seemed fine.

Perfect!

Well not so much.
I made some dinner had a brew or two, sent some emails and got ready to head home in the morning.
Went out the next morning to hook up and get on the road and it returned.
Thankfully it would clear and I could drive it. I headed off to Saugerties NY and the truck ran fine, no issues.
The next morning, same thing. It set the code, I cleared it and made if back to NH.

I was thinking mabey it was the NAPA ECT's and had one of my guys get 2 Motorcraft ones for me.
Thursday I fired up the truck, it went into derate mode, I cleared it and headed to the shop.

We deal primarily in European brands and have factory tools and software for them.
We do have a Snap-on Versus and some other stuff for the domestic and asian cars we occasionally work on.

I scanned the truck with the Versus and everything looked good. No codes and good data.
I took a Motorcraft ECT back to the campground with me and installed it that evening after the truck had cooled down.
Next morning, no change.
Start the truck, derate mode, clear, truck runs fine the rest of the day.

The shop is closed weekends so I went in on Saturday, and printed out a bunch of connector and wiring diagrams
I got busy with a DVOM and checked continuity, power, grounds, V-ref voltage ect.ect. It was all good. Then I started checking power and ground locations and connections.
Lo and behold G101, the ground on the right front frail rail was nasty.
I fixed it, gave the truck a bath, grabbed the Versus and headed back to the campground.
I was hoping that was the problem.

Sunday morning I scuffled out to the truck in my robe with a cup of coffee and the scanner.
I turned the key to run run position, counted to 5 and boom, Derate mode.
I didn't turn it off, plugged in the scanner and started scrolling through engine data looking at the various tempurature readings.
It was about 70 degrees out and that was about the temperature all the sensors were reporting.

With the exception of the EOT ( engine oil temp).
That one was reading 145 degrees.
It also set another P2560 code.
A little research showed Ford uses the same part # for both the ECT and EOT sensors and I had another brand new one at the shop.

I cleared the code, got dressed and drove to the shop. I watched the Oil temp all the way. It didn't start rising until the coolant temp was over 190 degrees.

The new EOT cured the problem.
The truck started fine Monday and Tuesday.
After I installed the two new ECT's down in PA it would only act up at the first start of the day and then be fine for the rest of the day.
No matter how many times I started or stopped it.
But it did it reliably every time I started it first thing in the morning.

I wonder if there's not some type of map or algorithm programed into the PCM concerning all the temp sensors.
I also wonder if there's a way to delete the derate mode as the truck is out of warranty.

I thought it was a rather odd problem and figured I post it here and perhaps save someone some aggravation.

I'm sure - a dedicated Ford Powerstroke guy will chime in and say " Oh Yea, that happens all the time" :-)
Fords have always been my choice for trucks.
European stuff is what I repaired for $$$$$

45bpcr.

 

45bpcr, I can't say that I have ever heard of that issue but any rate I am glad that you got it figured out and where able to share with the rest of us on how you fixed it.

 

Thanks for posting your experience. I also have a 2012 6.7L and always look for issues about truck and engine to add to my knowledge base!

 

This is a new one, never heard of anyone having this problem. Glad you got it fixed and was able to report how you did it.

 

I'll up-date this and say that was definitely the fix.
The trucks been running fine and the issue has not reoccurred.
Of course I am heading back down to PA tomorrow --------------------- :-)

45bpcr

 

Good luck with the Match, and the truck! I used to play Match Director for BPCR Matches in NM myself.

 

 

That happens all the time haha...only kidding lol......I know on my 2008 6.4 diesel I'm pretty sure if the oil temp and the coolant temp are outside of a specified range...it sets a code and if i remember reading correctly may also go into limp mode as well.
My guess...and this is only a guess here.....with your coolant temp sensor reporting 70 degrees and your oil temp reporting 145 degrees, a spread of 75 degrees your truck triggered limp mode as it thought your oil cooler was plugged up.
This is only my guess based on my 2008 truck....but i'm thinking yours would have similar parameters.