Have 2004 Diesel 3500. Twice in the last few years, truck has lost power while at freeway speeds and climbing hill. Each time, truck suddenly slowed to 25 mph but continued on. There were no warning lights or any other sign of problem. First time, dealer diagnosed bad fan clutch sensor and apparently the engine went into low RPM mode to save the engine. Second time, they found nothing wrong in engine diagnostics.

Anybody else heard of this? Any thoughts?

 

Fuel filter, but probably the lift pump. Have you checked for codes?

how to check for codes

 

Hey madhat, how come I can never get the code check to work in my 06? Do ya know? Thanks

 

I doubt it is the fuel filter or the pump or it would be a more common situation. More then likely a loose wire is present and when ti hits a bump or gets moister or some mysterious thing happens it sends your truck into limp mode.
Do you have a programmer or other add ons to the electricle system?

 

Nope... Slow down a little... is it a stick?

 

I will try again. lol Thanks, and no its a auto.

 

You watched the vid, right? I do not know if it's the same on an 06, but I did it on an 07.5, so I would assume that it's the same...

 

Ya, I watched the vid SEVERAL times. I am going out to the garage to try again. I have to walk through a blizzard in 5 below. Serious! It is nasty. Florida is looken real nice right now.

 

Yeah, Fl is... I'm from there...

 

Still couldn't get it Madhat. Lol. I am sure its just me. Tried it fast and tried it slow. My truck just don't like me I guess.

 

Does anything happen in the odometer window when you do it? Why don't you video tape you doing it and post it like I did?

 

Lol. I'm not that smart! Ha Ha. I will. I will post it a little later. No, nothing appears in the odometer window.

 

Could be trans temp and going into limp mode??

 

my 06 or early 07 thru numbers but none of them where any codes like the older trucks