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hey im new to the forum and i just purchased my first dmaxx. Its a 01 reg cab long box 4x4 with 116,000. my question is can you lock out overdrive on that year i have tried holding in the tow haul button but it wont lock out od it just turns on tow haul. also my truck is bone stock, and my buddy just put efi live on his truck and he has a extra ppe programer can i put it on my truck and just run the 90hp tune till i do exhaust and guages? thanks for any help
 

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Why do you want to lock out OD?
 

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Why do you want to lock out OD?

locking out overdrive is good for towing purposes, when your pulling a big climb you lock out overdrive so you would be in 4th making more boost and lowering the EGT's
 

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I never had a problem. I just put it in tow haul and let the allison do its thing.
 

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I thought that if you pushed it it will turn on tow haul but if you held it for like 3 seconds it will turn OD off? I won't have my truck till next week but I do remember being able to do this when I was using the truck last winter some pulling a tractor in Missouri's hilly country on some 2 laners.
 

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Hmm, interesting. Would all LB7 trucks be considered early 04 or was there an early/late split on them? Cause I am pretty certain mine locks out OD and it is an LB7.
 

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Yeah they changed in 03 and you can lock them out!.....01-02 the older body styles you can not lock of out!
 

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Let me do some digging I was question this a long time ago and found that you can you just have to wire a switch into the TCM that allows you to lock it out.
 
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