Has anyone had a factory software update done at the dealership in the last week or so? The car was in for unrelated problems and when I got it back, I noticed right away that it was not driving slowly very well at all. Coming to stops, smoothly accelerating away from stops and slow maneuvering, like putting the car in the garage. I called the dealer and ask if they had done a software update and was informed that they had done two. The problem appears to be in the shifting, and the clutch settings. Right as you come to a dead stop the car speeds up, requiring more brake pedal and then jerks to a stop. Extremely hard to modulate a smooth stop. On letting up on the brake pedal from a stop, the car does not creep forward, like it use to, but jerks forward quite fast, making it difficult to place in a tight spot in the garage. I have also had a few clunky shifts from first to second. There is no problems on the freeway or with aggressive driving. This is very disappointing as I have loved the new transmission very much. And for all that are going to suggest, I am taking it back to the Dealer.

 

Interesting. My HTC is exhibiting the same symptoms. It was built January 18. I received the car 2/16 and just crossed 300 miles. Sometimes going from drive to reverse or reverse to drive, the transmission will bang into gear. Driving slowly when the engine cold, the transmission behaves very jerky like it’s not sure which gear to be in. So far I’m not very impressed with this dual clutch transmission.

Please keep us informed what the dealer says.

 

If the SW update has caused this serious problem, I'd assume many more folks here would have experienced and discovered this problem too, since hard to park in the garage is an obvious issue that many others will notice too. Is the updated only to be done by the dealer, or could be done by owners? Could you please look up your SW version and post it here what's your current version? If it's indeed a bad SW update, maybe we all should avoid installing it until GM changes it.

 

I had those transmission problems since the day I bought the car along with a brake problem where I had to put way too much pressure on the brake peddle or the car would creep forward. Last week they updated the programing along with a radio update, my radio stayed on when the car was shut down and I got out of the car for about a minute or two. Drove the car home and did not notice the slow issues while slowing for a light or pulling into my driveway or into the garage. I had which I would describe as a bucking or hesitation while driving slowing in first gear.

 

Join the club mine does the exact same thing. Mine did this right off the Dealers lot. I dread pulling in my garage.
Here is my post from early January

https://www.corvetteforum.com/forums...ow-speeds.html

 

As I said before this behavior is NOT normal. My car has been fine since day one. Some people think there may be an initial jerkiness that goes away with use, but I never experienced it.

There's been no discussion of a recent update either. It would be good to see the update screen from OP's car. Go to SYSTEM > ABOUT > BUILD NUMBER

My car was last updated in November and it tells me there are no current updates. Here it is

 

Here is my update info. My transmission has been flawless from day one, problems only occurred after the update. Hopefully they just screwed up installing the update and can reinstall it. If that doesn't cure it, I would like them to put it back to the software before the update, problem is that I'm not sure if they would do that or not

 

Can you look up and post the update # as I suggested above?

 

Mine was built 12/10/20 I think the later builds are the ones having the jerking issues. They must have changed the software some where along the line.

 

Hi Dale, could you please look up the software version number on your center console screen and let us know what's the number? This would help all of us here in comparing the SW version you have with ours, and if your dealer confirms it's the update issue, all of us can avoid that update so we won't get into the same trouble you got.

Now, in terms of if it's dealer screwed up the update installation that caused the problem, it's unlikely, because if a SW package update isn't done completely, say, half way done and bombed, you typically won't have a working system at all. This is similar to your computer - let's say you are running a Windows update, and if the installation bombed or crashed half way through, in all likelihood, your won't even get the Windows to boot up. So if your dealer screwed up the update, chances are that you won't get the system to run at all.

You mentioned earlier that your dealer did two updates in a row. If you can ask them to tell you what are the updates they did (since each update has a description on them, or at least has a version number), that can help you understand what went wrong, and it may also help all the car owners here in terms of avoiding the problematic version of the update. Many of us have the car without that parking jerking problem, and if we can we should all avoid it - if it's indeed caused by an update.

If they indeed screwed up the update, chances are that they won't be able to reset the car to right before they ran the update. The best they can do is to reset to the original factory initial version, similar to on many smart phones and tablets, we can reset to factory settings with a certain key combination. I am not sure though, if the C8 computer has the factory version burned in that it can always be reset to that like mobile phones. If the dealer can do that, they can re-install some of the updates, and maybe choose to avoid the problematic one.



Not likely - if GM issues a new system SW for the same model year (in this case it's the 2020 model), they would push it down to all cars, unless some HW on the car has changed on a particular date that the SW update is only necessary for the cars produced after that date. And if that's the case, we would have heard many owners whose cars made after that date complaining about this problem too, but this doesn't appear to be the case judging from owners comments here - very few mentioned this.

 

I had the update installed last week while my car was in for service. I sure wish I had read this before having it installed. My car drives poorly at low speeds now. Before the update the transmission was flawless. I am going to call today and see if they can remove the update.

 

After the new software mine has a completely new build with no update history. I was informed that I cannot move to the previous software. Any one know if that is correct? My car drives terrible now.

 

My rule-of-thumb since migrating from an IBM 360-158 main-frame to my first desktop computer has been to never do any software updates on adequately working computers (at least until Windows 10). You can see why. Sorry about this, but it is in keeping with auto manufactures' computer acumen, imho.

 

When you installed the update last week, you must got a notification of update on the screen, right? Did you buy any chance took a photo of that screen, showing the update number? - your latest screen here does not show the update number.

There has been a new update from GM to some of our cars that built last fall, and the description was about "brake system under aggressive driving", which we have been suspecting that it could cause the problem making the car hard to stop at low speed, and we have been postponing that update. There's another thread on that, and the forum moderator John also got the update and he's not installing like some of us.

 

mine was built before the pandemic, from the dealer the car drove excellent smooth no issues very happy
took it back for an oil change 7500 miles and software update,
after the car was driving terrible jumpy impossible to control at a slow speed
The next day took the car back and they fix the problem, but the car was never the same, cant launch in 2.8 seconds any more
so next week going to an automotive shop to get the car properly tuned and put on a dyno

 

What do you mean by properly tuned? Last I knew, no one has yet to crack the encryption on the ECM.

 

Did they mention what they did to fix it? I don’t really trust them with my car for multiple reasons at this point.

 

The dealer did the install so I am unsure of what messages were displayed.

 

No shop is going to put a C8 on a dyno and "properly tune it". There is no tuning solution for the C8 ECM yet. The closest option will probably be by MOTEC and that will not be a cheap option at all.

 

So, we have now gotten at least 4 people - salemusa, 2KGreenC5, dgerstel, and hawk02, experienced this jerky transmission and hard to stop at slow speed issue, after installing an update from GM. This is quite serious, given that we don't know for sure exactly which update, and I and forum manager John have speculated the latest one we got might be the one that causes this issue and we have not been installing it, but so far we have no way to confirm this, since no one being the guinea pig to verify which update exactly. I bet there are are more folks getting this update and not knowing this potential risk, so there could be more people impacted by this after they installing it, yet there's no any message or announcement or TSB from GM warning folks about this. We don't even know if GM is aware of this problem and is looking into it. This is rather disappointing!