Hello,
I have had my 2004 6.0 4WD Diesel for almost 6 months.It now has about 22000K on it. About 6 weeks ago,we towed a 7500 pound TT from Montauk,NYto the Adirondacks and back with NO problems . (about 700 miles round trip.)We recently set out for hershey PA and when the truck hit 60-65 , 1750 RPM ,in or out of the tow haul feature, the truck would sputter, and blow black smoke , like puff-puff-puff out of the tail pipe. It would only happen at that speed, at the highest gear of the tranny , and when we towed. Needless to say , we turned around and went home. The next day we tried and tried to repeat the problem without the trailer, and could not. Three times, in the last 4 days we have hitched up the trailer and the truck does the exact same thing, at the exact same speed and RMP, and again, in or out of the tow haul mode. Otherwise, the truck runs mint, even pulling the trailer ....until you get to that speed. ANY ONE ever heard of this??? I am taking it to the dealer tomorrow, but was wondering what other owners think.PLEASE give me any suggestions!We bought the truck to tow the trailer, and take the kids camping.. and for now, we cant. THANK YOU!!!! Debbie ps I am nnot so sure how to use this site, so if you could email me as well as post on it, that would be great! mom1234@optonline.net

 

well sounds like the pcm needs to be flashed or reset you can bring it to the dealer for that

 

Thanks for your reply! What does pcm stand for, and do yo think the trucks computer can tell them that with out having the dealer road test it with the trasiler on it? Debbie

 

I really think you are going to have to let the dealer's diesel tech have a go at it w/the trailer in tow. If this is the only senario where the issues occurs, I don't see how they are going to diagnose any other way. Only thing I can think of is if this is a known issue and they already have a fix in for it. Maybe a PCM reflash which is no more than a new calibration file "flashed" or programed into the Powertrain Control Module.

 

There's your problem! The truck is worn out. 22000K is 22,000,000 miles! They were not designed to run 22 million miles, especially in 6 months! That's A LOT of driving!

Seriously, I agree that you need to take it to the dealer. That isn't right.
TSB 04-23-3 may help.

PCM is Powertrain Control Module. It is the truck's computer that runs both the engine and transmission.