Morning guys. I am curious about limp mode. Does this have anything to do with the engine, ie. pulled timing, reduced boost, or is it dealing with the transmission only? My mechanic swears that my code 2509 has my power down. I drove two, 2001 Ford F350's and an 04 Duramax and I swear the cumins felt just as strong as the Duramax and way stronger than the Fords. Should I be able to powerbrake this thing, and leave the intersection smoking? New to diesels and these common rails are spectacular if not daunting.

 

2000-newer dodge cummins automatics have a defuel wrote into the ecm/pcm that will defuel the engine if it sees 12psi of boost at less then 20mph if i remember correctly...had to install a BD Rad in my wifes 01 truck for drag racing because of this...could this be the lack of power your talking about?.....my 07 auto truck wont turn the back tires over sittin still at full throttle with the smarty on sw5 becuse of the defuel

 

That could be it friend. Maybe it is defueling. I am just wondering because after driving 3 other trucks including a 6spd Ford, the truck feels as good as the rest of them. I just refuse to add performance parts to a truck that may have issues.