C8 problems
Madison Wisconsin
Joined: Nov 2013
Posts: 504
Likes: 32
From: Madison Area WI
One thing I have noticed with all my new cars (20, 22 Vette, 22 Infinity, 23 Honda) is that there seems to ALWAYS be software bugs that pop-up and then go away. Except for the Honda which cant seem to reload google maps after a crashed map up-date that had to be started over. Ugh. Even the factory software trouble shooters can seem to find the problem, and they gave up telling me that it is now just something I have to accept. I think software problems are a normal part of any new car. The worst I have seen is my neighbors BMW EV. He has had to have the entire car's software deleted and reinstalled 3 times in one year. What is the answer? I don't know, but I sure hope they will find it.
Instructor
Joined: Apr 2020
Posts: 237
Likes: 145
From: Nashville
Well, after nine months GM has still not been able to figure out why my alarm randomly goes off when the car is locked. First time it happened was when I picked up the car at the dealer. I had locked the car while doing paperwork, and the horn went off. I assumed I had inadvertently hit the panic alarm on the fob in my pocket.
Since then, the alarm has gone off a couple of times a week by itself. The other day, while locked in my garage, the horn started blaring at 10:30 at night. Thankfully, it shuts itself off after 30 seconds.
Both GM and my dealer have been on this constantly, have downloaded all the logs, and replaced modules. It was even referred to the GM engineering group in Detroit. They were 90% sure they came up with a fix, sent out a new calibrated module, and had it installed at the dealer by an area service tech they sent in. A day later the alarm went off again. They even installed a module with a transmitter that would send live data to the engineers as the alarm went off. For the ten days that part was installed the alarm never went off once. The random nature of these events is what makes it so difficult to nail down what the actual cause is. It has happened at several different locations, so nothing in my home is causing it.
i was away from home for three months, the module was removed, and the car was left on a tender. Got back two weeks ago and the alarm already went off on three different occasions . I sent another email to my GM representative at the executive resolution team, and got a phone call the next day. They want another shot at installing the transmitter to see if they can finally isolate the trigger. If not, they said they will consider a buy back option for me. I still love this car, and would reorder the exact same spec. So, at this point I am waiting for the delivery of that new module and hope it catches the alarm going off.
What a pain. My car was held for five weeks in QC, and I wonder if this was the issue.
Since then, the alarm has gone off a couple of times a week by itself. The other day, while locked in my garage, the horn started blaring at 10:30 at night. Thankfully, it shuts itself off after 30 seconds.
Both GM and my dealer have been on this constantly, have downloaded all the logs, and replaced modules. It was even referred to the GM engineering group in Detroit. They were 90% sure they came up with a fix, sent out a new calibrated module, and had it installed at the dealer by an area service tech they sent in. A day later the alarm went off again. They even installed a module with a transmitter that would send live data to the engineers as the alarm went off. For the ten days that part was installed the alarm never went off once. The random nature of these events is what makes it so difficult to nail down what the actual cause is. It has happened at several different locations, so nothing in my home is causing it.
i was away from home for three months, the module was removed, and the car was left on a tender. Got back two weeks ago and the alarm already went off on three different occasions . I sent another email to my GM representative at the executive resolution team, and got a phone call the next day. They want another shot at installing the transmitter to see if they can finally isolate the trigger. If not, they said they will consider a buy back option for me. I still love this car, and would reorder the exact same spec. So, at this point I am waiting for the delivery of that new module and hope it catches the alarm going off.
What a pain. My car was held for five weeks in QC, and I wonder if this was the issue.
Le Mans Master
Joined: Aug 2004
Posts: 6,412
Likes: 1,295
From: Bluffton, SC
No, I did not leave the car locked while it was being stored in my garage, which was locked. Battery is fine and I have it go off even after long trips. So far, neither me, my dealer, nor GM can figure out what the cause is. Now, still waiting for their new test module which is hung up because of the strike's impact on parts.
Melting Slicks
Joined: May 2021
Posts: 2,562
Likes: 1,579
Thanks for posting this link that gives a very different picture that the JCTx post.
The above post gives a very one-opinion view of this excellent trannyaxle. These guys literally have decades of experience in building these things and it shows. Yes, the corvette provided challenges to the trannyaxle needs and designs to fit everything into a such a compact unit that delivers well. It was NEVER before done this small this many gears, this smoothness, and the ability to handle over 500HP/FtLbs.
The accomplishments of GM and their partners in this trannyaxle is beyond expectations. Can it be improved? Hell yes. As all engineering can. Can it be stronger and fit in the current space? How? Maybe with a stronger metal casing and bracing. Maybe with titanium, which greatly increases the cost. I for one have had 3 C8s so far. And not one single problem with anything at all. Not one. It is a dream tranny that will improve with the modifications to the current tranny and the redesign of the C9 tranny, now fully underway. A big congratulations to GM for giving us a super car at a Chevy price with a new-world efficient trannyaxle. What is not to like about that?
The above post gives a very one-opinion view of this excellent trannyaxle. These guys literally have decades of experience in building these things and it shows. Yes, the corvette provided challenges to the trannyaxle needs and designs to fit everything into a such a compact unit that delivers well. It was NEVER before done this small this many gears, this smoothness, and the ability to handle over 500HP/FtLbs.
The accomplishments of GM and their partners in this trannyaxle is beyond expectations. Can it be improved? Hell yes. As all engineering can. Can it be stronger and fit in the current space? How? Maybe with a stronger metal casing and bracing. Maybe with titanium, which greatly increases the cost. I for one have had 3 C8s so far. And not one single problem with anything at all. Not one. It is a dream tranny that will improve with the modifications to the current tranny and the redesign of the C9 tranny, now fully underway. A big congratulations to GM for giving us a super car at a Chevy price with a new-world efficient trannyaxle. What is not to like about that?
The TR9080 is an evolution of the DCT that was included in the Mustang GT 500.
https://www.tremec.com/noticias_deta...n-shelby-gt500
Also, major portions were designed and built by companies (aquired by Tremec) that had been doing DCT's for almost as long as I have been alive.
The TR9080 is such a turd that it was selected for the Maserati MC20!
https://www.thedrive.com/news/36339/...ercar-comeback
But hey, you can listen to negative bozos on forums all day...
Salty Veteran
Joined: Dec 2009
Posts: 571
Likes: 4
From: Orlando, Florida
St. Jude Donor '11
Check engine light (CEL) comes on and off arbitrarily.
Took the car to a different Chevy Dealership than the one I bought it from. Was told they need to keep the car for 3-5 business days. The car's exhaust valves needed to be reset due to the dealer installed Borla exhaust. Was told that it didn't fall under the warranty. A few days later the CEL lit back up. A short while later it went out but ultimately came back on.
I can't afford to have the dealer keep my car for a week at a time for this issue. I thought the reply from my service manager was very telling of their brand when I told them I needed the car to get around town. She said, "we have a shuttle."
I don't need a shuttle, I need a reliable car.
This issue started at 485 miles.
FML
Took the car to a different Chevy Dealership than the one I bought it from. Was told they need to keep the car for 3-5 business days. The car's exhaust valves needed to be reset due to the dealer installed Borla exhaust. Was told that it didn't fall under the warranty. A few days later the CEL lit back up. A short while later it went out but ultimately came back on.
I can't afford to have the dealer keep my car for a week at a time for this issue. I thought the reply from my service manager was very telling of their brand when I told them I needed the car to get around town. She said, "we have a shuttle."
I don't need a shuttle, I need a reliable car.
This issue started at 485 miles.
FML
Team Owner
Joined: Dec 2002
Posts: 32,074
Likes: 296
From: San Francisco CA
Check engine light (CEL) comes on and off arbitrarily.
Took the car to a different Chevy Dealership than the one I bought it from. Was told they need to keep the car for 3-5 business days. The car's exhaust valves needed to be reset due to the dealer installed Borla exhaust. Was told that it didn't fall under the warranty. A few days later the CEL lit back up. A short while later it went out but ultimately came back on.
I can't afford to have the dealer keep my car for a week at a time for this issue. I thought the reply from my service manager was very telling of their brand when I told them I needed the car to get around town. She said, "we have a shuttle."
I don't need a shuttle, I need a reliable car.
This issue started at 485 miles.
FML
Took the car to a different Chevy Dealership than the one I bought it from. Was told they need to keep the car for 3-5 business days. The car's exhaust valves needed to be reset due to the dealer installed Borla exhaust. Was told that it didn't fall under the warranty. A few days later the CEL lit back up. A short while later it went out but ultimately came back on.
I can't afford to have the dealer keep my car for a week at a time for this issue. I thought the reply from my service manager was very telling of their brand when I told them I needed the car to get around town. She said, "we have a shuttle."
I don't need a shuttle, I need a reliable car.
This issue started at 485 miles.
FML
Race Director
Joined: Aug 2016
Posts: 12,753
Likes: 10,184
From: Garden Valley CA
Check engine light (CEL) comes on and off arbitrarily.
Took the car to a different Chevy Dealership than the one I bought it from. Was told they need to keep the car for 3-5 business days. The car's exhaust valves needed to be reset due to the dealer installed Borla exhaust. Was told that it didn't fall under the warranty. A few days later the CEL lit back up. A short while later it went out but ultimately came back on.
I can't afford to have the dealer keep my car for a week at a time for this issue. I thought the reply from my service manager was very telling of their brand when I told them I needed the car to get around town. She said, "we have a shuttle."
I don't need a shuttle, I need a reliable car.
This issue started at 485 miles.
FML
Took the car to a different Chevy Dealership than the one I bought it from. Was told they need to keep the car for 3-5 business days. The car's exhaust valves needed to be reset due to the dealer installed Borla exhaust. Was told that it didn't fall under the warranty. A few days later the CEL lit back up. A short while later it went out but ultimately came back on.
I can't afford to have the dealer keep my car for a week at a time for this issue. I thought the reply from my service manager was very telling of their brand when I told them I needed the car to get around town. She said, "we have a shuttle."
I don't need a shuttle, I need a reliable car.
This issue started at 485 miles.
FML
Melting Slicks
Joined: Apr 2021
Posts: 2,755
Likes: 2,323
From: Simi Valley, CA
2022 C8 of the Year Finalist - Modified
My dealer installed the Borla S-type exhaust on my C8. Did the relearn procedure two different times before it "took" and eliminated the CELs. Many dealers will install after market equipment.
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Racer
Joined: May 2008
Posts: 399
Likes: 199
The dealership installed an aftermarket Borla exhaust system?? I find that strange. Most dealerships will not even install any aftermarket equipment much less warranty that part or void your warranty. What happened to that saying, "Keep it factory GM" or is it "Use factory AC Delco parts"??
Safety Car
Joined: Dec 1999
Posts: 4,714
Likes: 1,457
From: Virginia Beach, VA & Port Charlotte, FL
The dealership installed an aftermarket Borla exhaust system?? I find that strange. Most dealerships will not even install any aftermarket equipment much less warranty that part or void your warranty. What happened to that saying, "Keep it factory GM" or is it "Use factory AC Delco parts"??
Pro
Joined: Dec 2011
Posts: 653
Likes: 17
From: Fort Worth Texas
Window indexing problem
My 2020 C8 windows do not index. i've tried using the procedure to index from tjhe owners manual. it did not work. They will go up and down and works with express up and down
Drifting
Joined: Nov 2012
Posts: 1,670
Likes: 1,404
From: Central Ohio
you should post this in general section. Idk but you’ll have better visibility for someone to your your issue. Good luck! I believe I would start with resetting the battery though.
Melting Slicks
Joined: Dec 2006
Posts: 2,694
Likes: 106
Get your facts straight, fanboy: Both the GT500 and C8 came out in 2020, so IT WAS THEIR FIRST TIME!!! They're improving it, which is good, but it's NOWHERE as sophisticated as the German units, period. Saying otherwise would further prove your ignorance. And what's your problem with the name calling? You only look like a low-life bully, rather than a rational and educated person. I didn't insult your child, for crissakes. And if you treat your car like your child, you have serious issues. Ignored.
Drifting
Joined: Sep 2023
Posts: 1,520
Likes: 1,603
From: Franklin, TN
Get your facts straight, fanboy: Both the GT500 and C8 came out in 2020, so IT WAS THEIR FIRST TIME!!! They're improving it, which is good, but it's NOWHERE as sophisticated as the German units, period. Saying otherwise would further prove your ignorance. And what's your problem with the name calling? You only look like a low-life bully, rather than a rational and educated person. I didn't insult your child, for crissakes. And if you treat your car like your child, you have serious issues. Ignored.
Also, it is very similar in sophistication to the Porsche PDK. The TR9080 may not be as refined as the Porsche unit, but it is similarly sophisticated. The Porsche PDK is better but then again they have been working on it for over 40 years....
Last edited by winders; Oct 1, 2023 at 12:51 AM.
Racer
Joined: Jul 2013
Posts: 451
Likes: 120
From: Scotts Valley Ca
Yes, it is such a bad transmission Maserati uses it in the MC20.
Also, it is very similar in sophistication to the Porsche PDK. The TR9080 may not be as refined as the Porsche unit, but it is similarly sophisticated. The Porsche PDK is better but then again they have been working on it for over 40 years....
Also, it is very similar in sophistication to the Porsche PDK. The TR9080 may not be as refined as the Porsche unit, but it is similarly sophisticated. The Porsche PDK is better but then again they have been working on it for over 40 years....
Drifting
Joined: Sep 2023
Posts: 1,520
Likes: 1,603
From: Franklin, TN
Jeez, you guys think because a few people that post here have a bad transaxle means that some huge percentage of people that buy a C8 and have transaxle problems. That's just not the case.
Pro
Joined: Mar 2017
Posts: 722
Likes: 566
From: Northern Utah
Yes, it is such a bad transmission Maserati uses it in the MC20.
Also, it is very similar in sophistication to the Porsche PDK. The TR9080 may not be as refined as the Porsche unit, but it is similarly sophisticated. The Porsche PDK is better but then again they have been working on it for over 40 years....
Also, it is very similar in sophistication to the Porsche PDK. The TR9080 may not be as refined as the Porsche unit, but it is similarly sophisticated. The Porsche PDK is better but then again they have been working on it for over 40 years....
You say Porsche has had 40 years to refine their PDK? Well, after driving theirs, and driving my Vette, my hats off to GM. Their first attempt at this has been as flawless for me as the PDK in the Porsche. It shifts damn near identical. Actually I can say that GM's is a bit better probably because it was tuned for the Vette where the Macan is a Soccer Mom car. Never...another...Porsche.
Germans be freakin' crazy!
Avoid like the plague.
Drifting
Joined: Sep 2023
Posts: 1,520
Likes: 1,603
From: Franklin, TN
Yes, Porsche vehicles can have their share of issues. In my experience, Porsches have always been reliable and well built cars. Most of my friends in the PCA have had the similar experiences. But, there are a few people that have had experiences similar to yours. I feel for anyone that gets a "bad" vehicle. Whether it is a Porsche or a Corvette. But, in general, Porsches and Corvettes are well built reliable vehicles. I would not hesitate to own another Porsche. But, I am really looking forward to owning my first Corvette!
Racer
Joined: Oct 2020
Posts: 341
Likes: 254
From: H-Town (Pinehurst)
Just to further illustrate the point many attempt to make in regards to the reliability of the C8. I own a first year, 2015 Macan S. Much like my C8, ordered it sight unseen and took delivery in July of 2014.
Now some nine plus years later it has delivered absolutely rock solid dependability. No service issues whatsoever other than required maintenance, which is not nearly as extensive/expensive as many might believe.
Thus far my 2022 HTC C8 has been equally dependable albeit at just two years of ownership.
Sometimes it’s just the luck of the draw. Within nearly all makes and models you can have a problematic/frustrating vehicle and as is much more often the case…. not.
Now some nine plus years later it has delivered absolutely rock solid dependability. No service issues whatsoever other than required maintenance, which is not nearly as extensive/expensive as many might believe.
Thus far my 2022 HTC C8 has been equally dependable albeit at just two years of ownership.
Sometimes it’s just the luck of the draw. Within nearly all makes and models you can have a problematic/frustrating vehicle and as is much more often the case…. not.
Pro
Joined: Mar 2017
Posts: 722
Likes: 566
From: Northern Utah
Yes, Porsche vehicles can have their share of issues. In my experience, Porsches have always been reliable and well built cars. Most of my friends in the PCA have had the similar experiences. But, there are a few people that have had experiences similar to yours. I feel for anyone that gets a "bad" vehicle. Whether it is a Porsche or a Corvette. But, in general, Porsches and Corvettes are well built reliable vehicles. I would not hesitate to own another Porsche. But, I am really looking forward to owning my first Corvette!
FWIW, I love my C8 more than any car I've owned. And I still own a Ferrari Testarossa.
