LIMP MODE HELP [Archive] - Diesel Place : Chevrolet and GMC Diesel Truck Forums

: LIMP MODE HELP


VP02
04-14-2004, 01:42 AM
WHAT HAPPENS WHEN UR TRANNY GOES INTO LIMP MODE.. I THINK MINE DID BUT MY TRUCK IS TOTTALY STOCK?

Mackin
04-14-2004, 06:12 AM
It will default to third gear .... No reverse ...Illuminate the MIL ....





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VP02
04-14-2004, 02:44 PM
DOES IT NOT LET THE TRUCK GO OVER 2GRAND..

Mackin
04-14-2004, 03:29 PM
Uh huh in most cases .... Come'on spill it ... What'cha do ??


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AndrewFessler
04-14-2004, 04:30 PM
I believe my truck went into some form of limp mode last week at the track. Although I am not sure. What I do know is that the rpms where limited to no more than like 2200 and that the truck wouldnt shift out of 2nd.


I thought i broke something. I let the truck sit for a little bit and then all was well. (I did unhook my attitude for a moment too)


I do not know for sure though if I was indeed in limp mode.

VP02
04-14-2004, 04:49 PM
I WAS TOWING MY ENCLOSED TRAILER FULL OF WOOD FUNTURE FOR MY DAD UP THE GRADE IS SAN LUIS(PERTTY TUFF HILL) AND IT DID IT ON THE WAY WHEN THE TRALER WAS EMPTY AND WHEN IT WAS FULL BUT I DONT UNDER STAND MY TRUCK WAS BOUGHT IN OREGN BUT IT IS TOTTALY TO STOCK WAS DAD WAS WITH ME AND WAS LIKE WHAT THE HELLA. WHAT AM I GOING TO DO?

Mike L.
04-14-2004, 05:17 PM
VP02


I have seen stock Allisons go into limp towing. I think the TCM sensed too much torque converter slippage and went into limp. Usually after you clear the code all is well. You might have a converter clutch piston that wasn't quite machined correctly. Problem is, it will happen again when strained. If it's under warranty, go get a new trans, if it is not, time for an update.


mike

Rcher
04-15-2004, 08:24 AM
So how do you clear the code if it goes into limp mode? Does it have to go to a dealer? I will be towing 10,000 lbs thru the mountains in a couple of weeks so I should know just in case.


ThanksEdited by: Rcher

Mackin
04-15-2004, 08:34 AM
You can't without a Tech II or similiar product that is capable .... If you have someone close with a Quad tuner they can reset ....


The MIL will estinguish in a few cycles ...





Mac

hoot
04-15-2004, 09:55 AM
VP02


I have seen stock Allisons go into limp towing. I think the TCM sensed too much torque converter slippage and went into limp. Usually after you clear the code all is well. You might have a converter clutch piston that wasn't quite machined correctly. Problem is, it will happen again when strained. If it's under warranty, go get a new trans, if it is not, time for an update.


mike

My totally stock truck (GMC Dmax/Ally) way back when went limp on me the first time I pulled a load... about 7000 lbs.

Ends up I beleive it was overboost code... not the tranny.

Just remember.... there were issues with overboost/MAF codes that would cause the whole truck to simply drop power majorly. Not a trans issue at all.

Reflash cured it somewhat (still did it with propane)
Juice cured it completely.

emerick115
04-16-2004, 10:13 AM
I was told if you go into limp mode all you need to do is shut the truck off and wait 15 seconds, and then you should be able to go again. Have never tried it, its just what I heard.

Mackin
04-16-2004, 04:51 PM
I was told if you go into limp mode all you need to do is shut the truck off and wait 15 seconds, and then you should be able to go again. Have never tried it, its just what I heard.


Might take a little longer ,but you are correct ....


Stop ,shutdown,wait,restart .... The MIL will still be illuminated but the tranny will shift .... Taking into consideration actual damage or only slip detection ...


Mac