Hi all
I have an intermittent problem with my 09 F250 Diesel. A few times now under hard acceleration I have had the trans seemingly get stuck in 3rd gear. The little service required wrench symbol showed up on info screen but after shutting off the engine no codes were present. A week or 2 later this happened again and I ran diagnostics through my Spartan tuner and got P0771 and P2704 for codes. Again they cleared when I shut the engine off.
Since this is an intermittent problem, only after hard acceleration, would it make sense to change tranny fluid, maybe do a tranny flush? Or am I off to the dealership for a rebuild?
Richard
2009 F250 Lariat Crew Cab Short Box
Spartan DashDaq
S&B Cold Air Intake
4" Flange-back w/6" Can
Package by Dirty Diesel Customs-Red Deer Alberta

 

I know its likely destined for a rebuild, but we have a camping road trip planned so just wondering if I can delay the inevitable since its very intermittent and seems to go away as quickly as it comes on.

 

Do you have a tuner installed? How many miles since the last transmission service? how many miles on the truck?

 

Spartan Tuner. It only happens on the higher HP tunes, not on the tow tune. 52000 miles, trans not been serviced yet.

 

I think you have found your own problem then, bad tuning. Get that transmission serviced asap! I would contact the tuning company or whoever installed it and tell them the issue.

When you bring the truck back to stock does the issue go away?

 

It doesn't seem to happen at all on any tune other then the 310 hp one. Just wondering if it would be something more related to the tune itself or if the trans would likely be damaged. Its not really been misused, I run the tuner for MPGs and towing but never been raced or abused.