GM 8-speed

[86CUT]

The 8 speed problems seem to be software related according to 86CUT . He replaced the TCM and added a tune; all is mostly good in the 19 ZR1.
Therefore, it should be an easy fix for GM as they can throw the tune out over OnStar, not requiring a dealer visit. Just ask 69hurstolds

It does shift a lot bette indeed, BUT when its cold that is where it gets a little suspect with shifting even in Sport mode.

There has got to be a another MOD that can be done to handle this situation. Would be interestinsting to see if adding more fluid would help this issue as well?

 

[86CUT]

It is unreal that this affects all the high end GM vehicles that are $70K-150K, makes no damn sense they won't get this settled QUICKLY.
My Red Head sl*t has had similar issues.

 

[500/600]

So as I read through the posts, I wonder, so why are we keeping these G-bodies alive?....

Why? Because they look good. How? By replacing everything from gauges to tires and radiator to fuel tank with much better stuff than they came with. Some even completely reweld and re-engineer the frame. Why is all of that needed? We can’t stand driving that crap any more.

 

[Streetbu]

All you guys complaining, surprised you're not driving a Ford and on a Mustang forum. SMDH

 

[gnvair]

All you guys complaining, surprised you're not driving a Ford and on a Mustang forum. SMDH

The 6R80 in a Mustang shifts better than the GM 8 speed

 

[69hurstolds]

The 8 speed problems seem to be software related according to 86CUT . He replaced the TCM and added a tune; all is mostly good in the 19 ZR1.
Therefore, it should be an easy fix for GM as they can throw the tune out over OnStar, not requiring a dealer visit. Just ask 69hurstolds

Wait a minute. I'm not 100% SURE about all that. All I know is that out of the blue, the car (2020 CT5-VSeries) acted like an iPhone the other day requesting a software update to happen. I'm like WTF? So I delayed it via the touchscreen. So in order for the download to happen, you have to accept it, turn the car off, but it keeps the infotainment screen powered up and it locks the car down saying it cannot move, and no power accessories will work until the download is complete. Takes several minutes and you can go ahead and leave the car when it happens. I chose to stay and watch. It has a download progress bar and goes into minimum power mode (screen gets darker) during the download. Once it's done, it turns the power to the screen off like normal.

Now, the thing I am NOT sure of if it was simply BCM updates or if it could have been connected to the drivetrain software. I read something in the manuals about navigation map updates, I do recall an article I read on the Blackwing CT5-V development where GM would have the ability to update drivetrain or other vehicle software via OnStar which would almost make it impossible to do a performance tune unless you redesigned a lot of computerized junk. Is that here already? I dunno. Not even sure how much of that article was true anyway about drivetrain updates.

But I did find this from the CT5 information from GM...(note the last sentence in the first paragraph. Reads like a bad translation from some other language. ) What are they not telling us?

5. The flexibility to upgrade car tech features for years to come

The CT5 will be the first vehicle from Cadillac to come with the new digital architecture, enabling the vehicle to handle vast amounts of data, as high as 4.5 terabytes per hour! This is essential as our vehicles become more connect.

With an expanded capacity and over the air software updates, car owners can remotely upgrade the car’s high-tech features, active safety and Super Cruise Drive assistance features.

 

[olds307 and 403]

Our 2017 Dodge Challenger GT has had very few issues, just over 50K. Basically the horn didn't work and almost nothing else in that time. The Uconnect freezes every now and then and it needed new batteries in the remote. The 3.6 Pentastar is quite, powerful and solid, unlike the 3.5 in our other Challenger and the ZF8 8 speed is great. It tows well and sport mode is fun.
Other than styling on a lot, new vehicles are so much better than cars of the past. Look 200 hp is nothing for a 4 cyl and 300 hp for a V6 and everything is massively more fuel efficient. As said, the 68 to 72 cars from the big 3 hit the styling pinnacle. I saw a mid 60's base Pontiac 2 door, it was a blah square. The 66/67 cars were better than the previous years for styling, Bruce's 67 Olds is a good example. The 70's cars were ugly and terrible, the Oldsmobile powered ones were the most reliable. The 80's was better than the 70's but it doesn't say much. After that, GM especially sh*t the bed. Anytime GM came out with something decent, they would give it questionable styling, the GTO and many others or fatal flaws like the 4th Gen Firebird/Camaro, the 4L60E and 7 5/8" rear, come on GM, in something that started at 275 hp! GM's current styling is just beyond ugly, nearly it's whole product line makes me ill just looking at them. Ford and Dodge trucks look so much better along with the rest of their line up. Oh and GM dumping that great new hot V twin turbo Blackwing V8, rather than introducing it across multiple lines to make it more affordable to build shows how ridiculous that company has become.

 

[fleming442]

Pretty sure it's a standard function of OBD III......

 

[ssn696]

Just don’t hit ‘accept’ while cruising at 70. Then you too can be that Jeep guy.

 

[oldsmobile joe]

Wait a minute. I'm not 100% SURE about all that. All I know is that out of the blue, the car (2020 CT5-VSeries) acted like an iPhone the other day requesting a software update to happen. I'm like WTF? So I delayed it via the touchscreen. So in order for the download to happen, you have to accept it, turn the car off, but it keeps the infotainment screen powered up and it locks the car down saying it cannot move, and no power accessories will work until the download is complete. Takes several minutes and you can go ahead and leave the car when it happens. I chose to stay and watch. It has a download progress bar and goes into minimum power mode (screen gets darker) during the download. Once it's done, it turns the power to the screen off like normal.

Now, the thing I am NOT sure of if it was simply BCM updates or if it could have been connected to the drivetrain software. I read something in the manuals about navigation map updates, I do recall an article I read on the Blackwing CT5-V development where GM would have the ability to update drivetrain or other vehicle software via OnStar which would almost make it impossible to do a performance tune unless you redesigned a lot of computerized junk. Is that here already? I dunno. Not even sure how much of that article was true anyway about drivetrain updates.

But I did find this from the CT5 information from GM...(note the last sentence in the first paragraph. Reads like a bad translation from some other language. ) What are they not telling us?

here is what they meant to say. "This is essential as our vehicles become more woke."