Ok, not sure where to put this, but I will try here first.

A few days ago I hooked my simple little 3000lbs boat and trailer up to my 06 F-250 PSD. I have not had to tow anything In a few months. The boat trailer is a 4 pin connection, but the cord will not reach, so I used my adapter to reach the 7 pin connector. Took off from the house just fine, and went about 4 miles without trouble. Then at a stoplight, I hit the tow/haul button just to see what the difference was. It made a world of difference. All of it bad. Suddenly the truck would not shift until the RPM hit redline, then it would slam into the next gear. And when letting off the throttle, it would drop to idle instead of engine braking the truck. So after 2 minutes of this, I shut off the tow/haul mode. No change. It kept doing the same thing. Pulled off the side of the road, shut down the truck, restarted, and still no change, it kept shooting to redline, and slamming into the next gear. pulled off the road again, restarted again, still no change. Next we pulled the electrical connections to the trailer, restarted the truck, and was still doing it.
We limped home at 10mph or so, and took the trailer off the truck. Let the truck cool off, then took it out without the trailer. The issue continued for about 5 more minutes, then it magically went back to normal.
Hooked the trailer back up, and took it around the block, no troubles at all. Tried every combination of what we had done, and could not get it to do it again.

I took it to the dealer, and they told me that since there were no codes showing, they could not figure out what was going on.
Now I am afraid to hook up to another trailer, as I do not wish to cause damage to the truck.
But I have a 1500 mile trip with a 8000lbs trailer coming up, and I really do not wish to get stuck away from home. Does anyone have any ideas or has this happened to anyone else?

My truck is a 2006, 4X4 F-250 PSD crew cab Lairet short bed. with auto tranny.

 

Hook the boat up to the truck and head for the dealer if they will not help ask to see thew Ford district rep. One ride with what you describe should convince someone

ps did you check to see if the trailer brakes where applied wrong wiring ir a stuck surge break
Belfast

 

Thats the problem, I can't get it to do it again, with or without the boat. There are no surge brakes on the trailer, or wires other than for lights.

 

Chevy Convert, I have a 05 F-250 SD and have a issue with the tow haul also. Only mine is that it slams in so hard downshifting from 3rd to 2nd that you would think someone rearended you. Feels like the transmission is going to drop out. Ford says nothing wrong. Told me that the juice edge was the problem. So I disconnected it and let them reflash it. It still does it stock. But you never know when. It may do it 3-5 times in a row and then not do it for another 3 thousand miles. I know it will scare the you know what out of you. No more weight than your pulling forget it and just use the regualar transmission setting. That is what i do now and it works fine.

 

I found that less than a 5,000 pound trailer is not enough weight for Tow/Haul to function properly on these trucks. It's just not necessary to use with that light of a trailer, especially since Super Duty's generally weigh 7,000 to 8,000 pounds. When I tried Tow/Haul with my 3,000 pound pop-up trailer my truck did exactly what you've experienced so I never used it again when I towed that trailer.


You may want to try the TorqShift Relearning procedure in the 6.0 Tech Folder at the top of this forum. I did that and the Tow/Haul on my truck works flawlessly when pulling my trailer, 12,500 pounds. It's certainly worth a try.

 

Sounds like your PCM had a brainfart. These trucks are highly technical and everything is electronically controlled in them. Tow/haul should not act like it did whether you are towing a load or dead empty. Yes the rpm's will hold higher than normal and most shifts wont occur until you are at least over 2000 rpm's but they should'nt get near redline unless you are flooring it. If you can tow a trailer and try getting it to do it again than do so. If you dont want to tow the trailer then engage tow/haul without it and see if you can get it to do so. If you can, take it directly to the dealer and dont shut the truck down. I do agree that generally, tow/haul is not necessary with light trailers but it should work properly, regardless. It couldnt hurt to go with Kepler4's advice and try a TorqueShift relearn.

 

What is the general rule of thumb on that? When I was growing up(man do I sound old), everybody said to take it out of overdrive(another old age indicator) whenever your towing as long as there was a trailer behind you. Now I know we have came a long ways with automatic technology that that advice probably still isn't valid, but I never really found out when it was better to keep overdrive working(unless you could tell from the driving conditions that the road was demanding you to take it off) and you have this weight you might want to think about go ahead and taking od(or in this case turning tow/haul on) off before you get out the back gate. And I have seen people come back with tranny problems when all they were towing was a boat(just a little bass boat at that), but they had kept it in overdrive or didn't engage the tow/haul function(now that may have been related to some other problem that the tranny had and it was just a coincidence that it went bad when they were hauling I don't know).

 

I dont know that there is a general rule of thumb on it. I myself would feel that if you stayed under about 3k you would be fine not using it. Anything over that I would use it. The system is actually very smart and can adjust itself depending on weight, throttle demand and other factors. The other benefits are the engine braking and it provides and increased line pressures which help prevent tranny slipage. The only harm in using it with two light of a load or while empty is that you will burn more fuel with the higher shift points. With the TorqueShift whether you use it or not you do not delete overdrive.

 

I use tow haul usually when going down an off ramp to help slow the truck and I use it when not towing, also when going down hills not towing never had a problem.

 

Normally I agree with Russ, but in this instance, I would not try the relearn strategy. As I think that is what the truck was doing, learning. Especially if you cannot get it to repeat the symptoms. One thing I have leraned here is that these trucks don't do something "once" and never again if it is an issue. They will continue to do it over and over again. It may be a week or so apart, but they will show their face again if infact it is an issue. Several others here have reported similar experiences while towing with tow/haul for the first time and afterwards never having a repeat issue. (was mainly cruse control symptoms and erratic shifting up, not down) These trucks ecm/tcm do have an adaptive strategy, which means they do learn as you drive. They try to anticipate the way that you drive. If you change driving habbits, then yes by all means absolutly do the torqshift relearn proceedure.

 

You know Ryan, that's an excellent point. The adaptive strategy would make a difference and that's probably why he could not get his truck to repeat the problem.

I did the 'relearn' after I bought my larger trailer and it was probably not necessary.

Thanks for the info!

 

Interesting points. With all the big hills around here, I use T/H mode empty and it seems to work pretty well. If I want to stay off the brakes on an 8% downhill grade, I just push the button, tap the brakes and let the tranny do the work. It sometimes takes another brake tap to get it to engage when empty, but it works as well as under load. Coming down Ute pass at 8000' , I keep it there all the way down to maintain better control on the turns.

 

I have found, with all the program testing and reflashing that goes on with my truck, that the tow haul needs to relearn just like the regular driving cycle. Once it goes through some shifting and regular driving patterns it drives fine. In fact, I like it in tow/haul on these curvy mountain roads. Makes it more like driving a standard tranny and saves on brake abuse.

Like Ryan said....the tranny computer seems to have an occassional brain fart and for whatever reason act ignorant. If you truly have a problem with your transmission it will reoccur. More than likely it was a brain fart.

 

Ok.

Sorry to take so long to write again, but I have been unable to get near a computer for a while.

Update.
The truck still has not done it again. I tired every combination of with and without trailer, T/H on and off, that we could think of and the truck has not done it again.
So we took the truck out for a 1500 mile trip with a 8,400 lbs trailer, and I could find nothing wrong at all during the trip.

I think I will just file the event away and stop worrying about it unless it happens again.

I do want to say thank you to everyone that chimed in with information though. I REALLY appreciate having such a diverse group available to give second and third opinions on things like this.

Thank you all..

Eric.

 

Glad it was "nothing" and we were able to somewhat help you out.