What is LML TCM Tuning?  Do you need it? How does it work?

If you own a 2011 - 2016 GMC or Chevy Duramax (LML) you probably know it is equipped with an Allison 1000 transmission.  You probably know this is one of the most respected transmissions to ever be matched with a diesel engine.   The Allison's smooth shifting and stellar reliability have earned it a special place in the diesel performance community.  

With all the benefits this transmission provides, it's not without it's own short comings.  Many LML owners have noticed there are times when it just doesn't shift they way want it to.  And when LML owners have questions, they know to call DuramaxTuner.com for help.  

Below you will find the 3 most commonly asked questions and answers on this topic.  

What is LML TCM Tuning?

LML is the RPO code used at General Motors for the 6.6L diesel engine equipped in the 2011-2016 model HD pickups. TCM is the an abbreviation for Transmission Control Module.  Tuning, in this use, is an aftermarket adjustment to the calibrations that are programmed by the factory.  Now that the definitions are out of the way, we can talk about what it actually means for you.  

Ever feel like the truck is lugging in a gear when you want it to up-shift?  That is the adjustable through a shift schedule in the tuning.  Or, do you ever wish it locked the torque converter more intelligently?  The torque converter is commanded through the TCM tune which means with TCM tuning we have full control. 

The LML Allison 1000 is the first to offer electronically controlled line pressure.  This is a huge advantage for diesel performance enthusiast.  Increasing line pressure in the transmission with the right strategy results in better clutch holding capacity.  The working theory is this will help keep things together longer.

Do you need it?

The factory does a great job keeping these smooth shifting with light to reasonable throttle inputs.  The Allison 1000 is also known for shifting well at Wide Open Throttle (WOT).  However in the mid to aggressive throttle inputs it is less than desirable.  Shifts can feel like they flare or just seem to take forever to get from one gear to the next.  

This means if you drive like I do, aggressively, it will be a night and day difference.  Also, for you "Adult" drivers there is still a distinct impact on drive-ability.  Towing performance is improved as well and yes, you still use Tow Haul mode.  TCM Tuning is designed to help improve your windshield experience.

Second and Third gear starts are available for you if sled pulling or drag racing are your thing.  Make sure to give us a call and discuss this for your application though.  We want to make sure it is going to help your situation.  

** You will NOT need TCM tuning if you have a hard parts issue.  If the transmission is broken, TCM tuning will not fix it.  

How does it work?

That depends if you have ECM (engine control module) tuning already your LML or not.

If you already have LSP Tuning (LML Switchable Positioning or Switch-on-the-fly) or the standard LML SPADE from DuramaxTuner.com adding TCM tuning is easy.  Simply give us a contact us with your VIN number and a TCM tune can be emailed to you.  After a little drag and drop action with the computer, you can flash the tune on your truck.  

Have your truck tuned by someone else?  You will just need either a V2 (or another AutoCal) to flash the tune.  

Now you know what LML TCM Tuning is, if you need it, and how it works. The next step is to !  Click the button and fill out the corresponding form.  One of our diesel performance experts will follow up to answer any and all of your questions.