Anyone perform the transmission reset and relearn on their A8? Is that really a thing? Did it fix any issues? Did you get it done at the dealership? Approx cost?

My 2017 GS comes to a stop with a jolt as it shifts from 3rd to 1st. Very annoying.

 

I’ve had a “Reset Adaptives” and “Fast Learn” done a couple times. I had a hard downshift right after a trans valve body replacement. I brought it back in and they did a relearn to fix it.

 

I had Shift flair , did the reset and all is well , don't know how much it costs because I did it myself using my GDS2

Why are u considering it ? What problem are u trying to solve ?
Dave

 

As I come to a stop their is a strong jolt as it shifts from 3rd to 1st. Would the relearn fix that?

 

Yep , make sure they do the full Clear Adapts and then Garage Relearn with GDS2 , then they need to do drive cycle . They can short cut it and do the manual Relearn but I have found that that rarely works ! You're car will still shift a little funky for the next 50 miles or so as it relearns each shift RPM , timing and preasure that it takes to make a perfect shift . Make sure during this time you drive it like you stole it as you want to make sure you cover all the bases And then afterwards once in a while because of the adaptive nature of the programing in a A8 you need to drive it hard . I am not sure if you saw my post that included a link that explains a lot of the problems with the A8 and what the solutions are , tge relearn i. This article is the manual relearn where you concentrate on each clutch. it's much faster to just do the full relearn using GDS2 , HPTuners or other diagnostic software .

My trans shifts as well as my wife's AMG

https://www.corvetteforum.com/forums...8-article.html

Dave

 

Thanks for the info and link. I would rather do this myself than take to a dealer if possible. I have trust issues.

Are you saying that with a GDS2 tool I can do it myself? Is there a particular GDS2 that you would recommend?

Are there documented instructions on how to do this?

thanks

 

BEST FLAIR SHIFT EVER

 

Thanks for the help Har_ray ....really helped the guy out a lot !

Dave

 

@capeli
So... this is a complicated answer. Not knowing your mechanical or computer ability I would recommend somebody who already has the tools and knows how to use them, if you don't have anybody, then find a dealer or a transmission shop that you trust.

GDS2 is proprietary GM diagnostic software, there is only one OEM software for a CAN BUS equipped car like a C7 corvette. Where there is the difference is the MDI communication device that talks to the car thru the OBD port, there is GM MDI made by Bosch a few China made MDI that are BOSCH look alike and a few manufactures who make BI Directional scan tools with software like a Snap On Modis scanner, and then there is VXdiag , made in China and is a Knock Off MDI device that comes with a " Licensed " copy of GSD2.

1- To buy and license the real GM GDS2 plus buy the real GM MDI communications device from GM is really expensive.... there are other BIDIRECTIONAL scan tools on the market Like Snap On Modis or HP Tuners that are less expensive that have the capability, most transmission repair centers have them. and then you have the VXDIAG for $129.00 on Amazon,

2-So what's wrong with VXDIAG? no support at all you have to download their software from a Chinese web site, loading the software is a crap shoot and if you have a question, they will do their best to answer it but the translation to English leaves a lot to be desired. you really need to be proficient in computers to get this thing up and running, they even offer an option to buy an SSD with the software already loaded, If you get it loaded its solid as a rock and works great. I have had mine for over 5 years now, I have updated firmware on my car and a few of my friends' cars I have helped guys load it on their laptops, some we had no problems, then we helped people that had a few issues loading it , but we got thru it and then there is a few that just sent it back to Amazon. One guy even wanted to complicate matters and use the wireless version of the VDIAG , I told him it was hard enough getting the wired version to work without throwing in wireless, it was really important for Him so he and I persisted and finally got it working but for firmware upgrades, I would not trust it.

3- You could download HP Tuners for free , then buy a HPTUNERS device and then buy 4 credits , 2 for engine and two for the TCM , HP tuners can reset ADAPTS and do the relearn , HP tuners does not have any documentation, you would need to go to the HPT forums and read up on it but remember when you get to this level , you do something wrong and your trans or any module you might be working with is toast including the ECM

4- There is not any directions on anything with GDS2 ... so you better know what you are doing before you press any buttons because GDS2 is a really powerful software that can access EVERY module in the car, press the wrong button and you can mess stuff up so it's not for somebody who does not have any mechanical ability or knowledge of what and how each module works . you can buy the GM diagnostic and repair books that outline what you are supposed to do but again, they are expensive.

I have HP Tuners and VXdiag I do all my own work and have been for years but there are times when even I am scared to do something, so I reach out to my many friends in the repair business for help. One time the while doing a relearn for a friend the system did not finish and timed out. His car would not go into gear, lucky for me it was not too late in the evening, and I was able to reach out to one of my friends in the business. Come to find out all we had to do is remove the battery cables and then put them back on to force a HARD reboot of the TCM module, the module will realize that the reset failed and just revert to previous preset values, this scared the heck out of me, but I guess thats how you learn.


If you are going to work on your car yourself and are not scared of that type of thing, then by all means purchase one of teh MDI devices and GDS2 or HP Tuners, if you are only going to do this once in a while ... it's not worth it, just pay the dealer a few hours of labor as it will be cheaper in the long run.

If you still are interested in doing this yourself and maybe doing other stuff after reading all of this .. drop me an email DCASOLE AT COMCAST.NET so we can talk further. I can try and help you out and would be glad too but I make no guarantees.

Dave

 

dave
are you able to firm up your transmission shifts with like Hp tuners?? Kid of curious. As I’ve read about people tuning just the trans pcm.

 

So need some claification on what you mean by "firm" up shifts, what are you trying do do ?

Even when stock my car shifted hard and fast whenever I was standing on the gas pedal so I am not sure what you are trying to achieve .
I am juat learning HP tuners so I am leaving the tuning to the pros as there are to many ways you can mess stuff up . Yes you can acess the TCM on most ( some are locked ) I had my trans tuned when it was stock and I had it tuned again after procharger install

Dave

 

I would like to make the shifts harder if possible
And yes i was told my Tcm is locked on the 17 grand sport. It would have to be sent to hp
tuners. Total cost around 7-800 w tune 🤷‍♂️

 

I think they can now unlock the 17 thru 19 without having to send the TCM in now , I am positive a Diablo tool can
As far as shift harder , i dont want to disappoint you but this is not the old days where you put a B&M valve body in your turbo 400 3 speed and it would snap your neck shifting or chirp the tires , OH how I remember those days


Inorder to handle the large amount of HP that these trans can handle they were designed way different than the old trans . The ECM actually cuts engine power for micro seconds while the trans shifts and the adaptive learning knows how much preasure to apply and the timing to apply it to make a perfect shift every time

My tuner modified something in my tune when I installed the procharger but even before this tune my trans shifted perfectly


During wide open throttle my a8 shifts perfectly, shifts really fast and does not slip , why would you want it to shift harder than it does ?? All you will end up doing is breaking something or upsetting the car when it shifts

Your best bet would be to talk to an actual Tuner .....

Dave

 

makes sense. I get what you’re saying. I never really get on mine. Just normal driving. But I do drive the A8 in manual mode and in sport mode.

 

find a safe spot , nobody around , put it in sport or Race mode , get up to 35 MPH then kick it hard stay into it till it shifts , then tell me how big your smile was

​​​​​​​Dave

 

I’ll give that a try. Never have done that

 

hey dave

so I asked Nic D. One of the best timers out there. Here was his reply on Tcm


That process hasn't and won't change as HP Tuners are the only ones that can do the unlock procedure. Once it's been unlocked I can tune it and yes it would improve the speed and firmness of the shifts. The little bit of delay that is there between the paddle pull and the actual shift can't be changed but the shift itself would be quicker and firmer

 

That's awesome but ... remember it won't feel like that turbo 400 that you increased the line preasure on lol lol

​​​​​​​Dave

 

plus I think the cost is around $700 to do. So probably not worth it