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Hesitation DESIGNED into truck

Brian-Spokane
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Brian-Spokane Enthusiast

Brian-Spokane

Posted
Posted

After going through a Lemon Law case, and loosing, because of hesitation in my 2018 GMC Z71 1500, I learned a lot about what's going on.  The BOTTOM-LINE - GM is intentionally detuning our trucks.  This is undisputable.

 

During the deposition phase, GM acknowledge they are intentionally detuning the trucks in an attempt to save approximately 1-2 mpg.

 

What was I experiencing:

  • Hesitation when in Active Fuel Management mode.
  • Hesitation when lightly pushing on the gas
  • When pressing on the accelerator peddle the power was delayed getting to the rear wheels
  • When getting on the gas pedal immediately after braking, there is a HUGE delay
  • When lightly pressing on the accelerator pedal, the RPMs actually go DOWN (WTF???)
  • When going 30 mph the vehicle is already in 6th gear and lugging.  This one detuning trick, turns your 350hp vehicle into a Subaru.
  • Extremely slow transmission control to shift into a lower gear.
  • Extremely fast transmission control to shift into a higher gear.

 

So, after loosing, what did I do to fix these issues?  I paid to have the truck re-tuned.  I waited to almost 60,000 miles when the warranty expired.  I am kicking myself for not doing it sooner.  I am not affiliated with this guy at all, but I will tell you LEW at diablewtune.com fixed 95% of the issues and I can FINALLY enjoy the drivability of the vehicle, as I would have designed it.  It actually pulls hard from a dead stop.  I can actually smoke the tires if I wanted.  YES, performance over economy in every situation ... finally!

 

So for all you potential buyers out there, don't waste your time.  Drive it off the lot and don't hesitate like the truck hesitates and give your vehicle a performance tune immediately.

 

davidr83 Enthusiast

davidr83

Posted
Posted

Lew does good stuff! I've had him do a couple tunes for me back in the day on a 08' Sierra 5.3L with bolt ons/nitrous and on a 13' Denali with bolt ons. Back when he did my tunes, he was limited on what he could do compared to what HPtuners could at the time, but non the less his tunes made a great improvement for drivability and performance over stock tunes.

 

He's a member on the www.performancetrucks.net forum and others there can vouch for him too.

  • Thanks 1
aseibel Senior Enthusiast

aseibel

Posted
Posted
28 minutes ago, Brian-Spokane said:

GM acknowledge they are intentionally detuning the trucks in an attempt to save approximately 1-2 mpg.

Yeah. not shocking at all.

The government and CAFE have their hands in everything. Fuel economy is king. They don't care if you can smoke your tires, they want you to get 1 more mpg.

 

I'm glad you are finally happy with your truck. Modifying the the tuning is your choice.

But this will never change for new passenger vehicles, too much regulation.

newdude Senior Enthusiast

newdude

Posted
Posted (edited)

This is not news.  Its called Torque Management.  All designed to protect the engine/transmission for reliability/durability.  Also the millions of these they build have to meet EPA/CAFE/CARB regulations.

 

I guess I'm not sure why you are "shocked" that this is the case.  You've learned the hard way what many have already known.   

Edited by newdude
  • Like 3
EricTheRed Enthusiast

EricTheRed

Posted
Posted (edited)
8 minutes ago, newdude said:

This is not news.  Its called Torque Management.  All designed to protect the engine/transmission for reliability/durability.  Also the millions of these they build have to meet EPA/CAFE/CARB regulations.

 

I guess I'm not sure why you are "shocked" that this is the case.  You've learned the hard way what many have already known.   

Newdude, aren’t you a GM Tech or something? Tell me, does the torque management software help with wear and tear on parts and components too?

Edited by EricTheRed
Brian-Spokane Enthusiast

Brian-Spokane

Posted
  • Author
Posted

NewDude it's really very simple.  Push on the gas, vehicle goes.  Release the gas, the vehicle slows down.  No exceptions. 

 

What  will the libs do next?  Implement a system where we have to answer "Are your sure" on the infotainment system every time we push on the gas?

  • Haha 1
Rob Mugs Enthusiast

Rob Mugs

Posted
Posted
4 hours ago, Brian-Spokane said:

NewDude it's really very simple.  Push on the gas, vehicle goes.  Release the gas, the vehicle slows down.  No exceptions. 

 

What  will the libs do next?  Implement a system where we have to answer "Are your sure" on the infotainment system every time we push on the gas?

Just now... someone in California saw your response and is drafting a law just for this.

  • Haha 1
CamGTP Senior Enthusiast

CamGTP

Posted
Posted (edited)
6 hours ago, Brian-Spokane said:

NewDude it's really very simple.  Push on the gas, vehicle goes.  Release the gas, the vehicle slows down.  No exceptions. 

 

What  will the libs do next?  Implement a system where we have to answer "Are your sure" on the infotainment system every time we push on the gas?

 

Feel free to read how these computers work.

 

http://www.hptuners.com/help/vcm_editor_tuning_how_to_advanced_e78.htm

6 hours ago, EricTheRed said:

Newdude, aren’t you a GM Tech or something? Tell me, does the torque management software help with wear and tear on parts and components too?

 

Yes, it does. Transmissions must have a way to pull torque away. We don't get the luxury of something like a dual clutch transmission were it can zing between gears without any lag time. It doesn't need to pull timing away as much, doesn't need to wait for the off going clutch release and the on-coming clutch fill with fluid and grab. Granted all this happens super fast but there is still a lag time that it needs.

 

 

The torque model is also used in everything about how the engine and transmission operate. This was a change over in 2014 with the new DI engines.

 

The TM and logic behind all of this could have it's downsides though. The longer the shifts the take, the more slip they build into the calibration and things like that can put wear on technically "wearable" parts like the frictions/steels and torque converter. If it lasts until the warranty is up that is all GM is going to care about. After market tuning and aftermarket upgrades can be cure most of these problems in some vehicles.

Edited by CamGTP
Brian-Spokane Enthusiast

Brian-Spokane

Posted
  • Author
Posted

I had the commander. GM has detuned our trucks using many methods (see my original post). The commander addresses only one issue. I found myself still frustrated with the driveability of the vehicle. So, I decided on getting a performance upgrade from Lew.  I am very thankful for his knowledge and ability to make my truck operate like it should. No regrets here. Well worth the money! 

It's Tim Senior Enthusiast

It's Tim

Posted
Posted
29 minutes ago, Brian-Spokane said:

I had the commander. GM has detuned our trucks using many methods (see my original post). The commander addresses only one issue. I found myself still frustrated with the driveability of the vehicle. So, I decided on getting a performance upgrade from Lew.  I am very thankful for his knowledge and ability to make my truck operate like it should. No regrets here. Well worth the money! 

You keep blaming the messenger... this is why we need tort reform, loser  ?  pays.

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