Please excuse my ignorance, but will someone explain to me what is meant by 'limp mode'. ( I am, of course, refering to the truck.)

When ya got too much HP goingf to the wheels with a stock Allison as a fail safe one of two things will happen, stuck in third gear or Neutral.


It has happened so may times for me I do not even set a code, you can feel it starting to go and if you get out of the throttle fast enough you can avoid the SES - P0700 code from being set.


Zinging is the new favorite term for limp mode.





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Man all this time I thought limp mode was when you got your six speed so hot the shift lever just layed over on the floor after a few minutes of hard use.http://www.dieselplace.com/forum/smileys/Big Smile.gif

limp home mode is the term used to say when the vechicle
pcm see a problem it cuts back the fuel injection rate
on the duramax it cuts 4 of the 8 cylinders. 2 from each bank or what gm calls injector control circuits.

I thought that limp mode had to do with engine...sensing a problem and giving you half power just like patrick said.


I thought the trans sensed slipping and only gave you up to the gear that slipped.


I thinkhttp://www.dieselplace.com/forum/smileys/Ermm.gif

The tranny limp is like Tony described. The engine will limit rpm to 2000 when it senses a problem. It has full power up to 2000 but with an auto it is tough to get anywhere.

I did not know there was a tranny limp also. I know the getting stuck in 3rd gear happened to my friend and he had to shut off the engine and restart....cleared the limp and he was on his way again.

as a d/max teck never head of a tranny limp home seen a no shift and slip ses lamp on for trans related problems.

You don't have to go back to the dealer if this happens do you? Is there any other way to reset the SES light if this problem happens. This would be helpful to know

I believe the SES resets itself after 5 restarts, but the code stays in the TCM so they can get it with a Tech 2 later.

yes you can reset the ses but if it is a hard code or active it will defalt to limp mode.