Acceleration "dead spot" - AMG GLC 43 coupe
Member
Joined: Jan 2021
Posts: 101
Likes: 43
GLK350 2013, GLC63S AMG
I have glk 350 and glc63, glk has no such problem and is absolutely predictable in any situation. They overcomplicated new cars with bunch of those tcu cpc modules and it feels like they have miscommunication glitches.
Newbie
Joined: Jan 2023
Posts: 8
Likes: 7
2020 GLC 43 AMG
MB decided there wasn't an issue and told me they were not going to do a buy back. I did more testing and I believe I've found th issue. I thought that when I saved my custom drive mode settings, I was also saving the active braking in a disabled state. It comes back after every restart. If you don't fully power the vehilcle off, you'll get some odd errors in the active assit view between the gauges. What I've found is that the active assist is constantly braking but mostly unnoticeable. This is visible via the last time active assist was activated. That timer is constantly being reset as you drive which means the car is constantly braking at levels that you may or may not notice. It's only until it brakes when you're trying to cross three lanes of oncoming traffic that you really feel the car stop completely. The cameras and software that are trying to nanny you into being safe are actually going to kill someone. We're trading the car in and making this someone else's problem. We're going to eat about $10K OR we spend at least $10K on a lemon law lawyer and have them handle it. Trading it in sounds cheaper at this point but we'll at least contact someone for a consultation. I will create a video and post this to YouTube before we get rid of the car. Happy to damage this brand as much as possible before we get rid of the last Mercedes we'll ever own.
Last edited by liminal; Jul 12, 2023 at 01:36 AM.
MBWorld Fanatic!
Joined: Jan 2023
Posts: 3,132
Likes: 1,205
GLE 580
MB decided there wasn't an issue and told me they were not going to do a buy back. I did more testing and I believe I've found th issue. I thought that when I saved my custom drive mode settings, I was also saving the active braking in a disabled state. It comes back after every restart. If you don't fully power the vehilcle off, you'll get some odd errors in the active assit view between the gauges. What I've found is that the active assist is constantly braking but mostly unnoticeable. This is visible via the last time active assist was activated. That timer is constantly being reset as you drive which means the car is constantly braking at levels that you may or may not notice. It's only until it brakes when you're trying to cross three lanes of oncoming traffic that you really feel the car stop completely. The cameras and software that are trying to nanny you into being safe are actually going to kill someone. We're trading the car in and making this someone else's problem. We're going to eat about $10K OR we spend at least $10K on a lemon law lawyer and have them handle it. Trading it in sounds cheaper at this point but we'll at least contact someone for a consultation. I will create a video and post this to YouTube before we get rid of the car. Happy to damage this brand as much as possible before we get rid of the last Mercedes we'll ever own.
https://www.nhtsa.gov/report-a-safet...le-information
Newbie
Joined: Sep 2021
Posts: 11
Likes: 1
AMG GLC 43 Coupe
MB decided there wasn't an issue and told me they were not going to do a buy back. I did more testing and I believe I've found th issue. I thought that when I saved my custom drive mode settings, I was also saving the active braking in a disabled state. It comes back after every restart. If you don't fully power the vehilcle off, you'll get some odd errors in the active assit view between the gauges. What I've found is that the active assist is constantly braking but mostly unnoticeable. This is visible via the last time active assist was activated. That timer is constantly being reset as you drive which means the car is constantly braking at levels that you may or may not notice. It's only until it brakes when you're trying to cross three lanes of oncoming traffic that you really feel the car stop completely. The cameras and software that are trying to nanny you into being safe are actually going to kill someone. We're trading the car in and making this someone else's problem. We're going to eat about $10K OR we spend at least $10K on a lemon law lawyer and have them handle it. Trading it in sounds cheaper at this point but we'll at least contact someone for a consultation. I will create a video and post this to YouTube before we get rid of the car. Happy to damage this brand as much as possible before we get rid of the last Mercedes we'll ever own.
After having a GLB loaner for a month with all of those “assistance features”, I was happy I do not have them on my regular vehicle and I nearly got into trouble no less than four times. Two examples:
The rear cross traffic alert applied the brakes when nothing was around me (not even ghosts).
It did it again when it thought I was too close to an oncoming car when the car was at least one tractor-trailer away from me.
As to your last comment, you can never do enough damage to Mercedes to stop anyone from buying them, as they make excellent cars.
Newbie
Joined: Jul 2023
Posts: 1
Likes: 0
AMG GLC43
2020 AMG GLC 43 coupe here in Charlotte, NC, which I've had for about a year. My driving style with this vehicle isn't different in any relevant way versus with past vehicles. There is an acceleration dead spot which is the default occurrence when I am coasting at a low speed and then go to accelerate. Common scenarios are driving toward an intersection and rolling forward as you determine if you are clear to go and then accelerating, or slowing down to let a car in the lane next to you go by so you can then switch lanes and accelerate. I swear, I've almost gotten killed a few times when I had time to go but only if I hustled; depress the accelerator, and nothing happens for a full second. Then I go from having enough time to almost getting hit.
MB local dealer where I got the car provided no answers or solutions. Of all the damn ironies, coming back from that dealer after the most recent service appointment, I had to slow down due to a car in my lane waiting to turn left, then tried to gun it to get into the next lane over, and...nothing, just no response. That time I actually aborted the lane change before the acceleration kicked in.
It doesn't do this in any other set of circumstances, not from a dead stop, not when I accelerate quickly after coasting downward to 20 mph (for example). I wonder if anyone else has experienced this or has thoughts? Thank you!
MB local dealer where I got the car provided no answers or solutions. Of all the damn ironies, coming back from that dealer after the most recent service appointment, I had to slow down due to a car in my lane waiting to turn left, then tried to gun it to get into the next lane over, and...nothing, just no response. That time I actually aborted the lane change before the acceleration kicked in.
It doesn't do this in any other set of circumstances, not from a dead stop, not when I accelerate quickly after coasting downward to 20 mph (for example). I wonder if anyone else has experienced this or has thoughts? Thank you!
To me that's not an adequate response, that they all have the same problem. What he did explain was that in comfort mode and in second gear, which is typically the gear it will be in under that circumstance, is that the transmission is working out which gear to be in.
Personally I think it's a flaw. For a car worth $140k AUD and with all the alleged engineering that goes into these cars MB have clearly missed this one. It should not lag like it does, and as you say, it's dangerous.
We bought ours new and only after a couple of drives noticed the problem, has always been there when I drive it. To avoid it I need to feather the throttle on but still need to be careful when pulling out on busy roads.
I will follow this up with the MB dealer and see if I can get them to do something.
Cheers
Newbie
Joined: Jan 2023
Posts: 8
Likes: 7
2020 GLC 43 AMG
I'm telling you guys, it's the active assist. Pull that menu up in the center console view and you'll see it braking all the time even - it's not noticeable most times but it's recording a braking event on a regular basis. Last night I was driving at slow speed through an outdoor shopping center and the car suddenly slammed on the brakes as if someone had stepped in front of the car. I thought someone did. Nothing. There was someone standing on a curb on the opposite side of the road but that was 25 yards ahead. No cause for concern going 10-15mph. Later I got out on the road and with no other cars beside or in front of me the collision warning starts beeping and flashing on the dash. There's something wrong with the **** nanny cams they've put in these cars. Their attempts to make this car safe are making it more dangerous to drive. If someone does get injured or dead, there will be no way - other than this thread - to trace it back to MB. I'm not suicidal!
Senior Member
Joined: Mar 2018
Posts: 397
Likes: 55
2010 Audi S4, 2019 GLC 43,07 BMW Z4 M coupe
I'm telling you guys, it's the active assist. Pull that menu up in the center console view and you'll see it braking all the time even - it's not noticeable most times but it's recording a braking event on a regular basis. Last night I was driving at slow speed through an outdoor shopping center and the car suddenly slammed on the brakes as if someone had stepped in front of the car. I thought someone did. Nothing. There was someone standing on a curb on the opposite side of the road but that was 25 yards ahead. No cause for concern going 10-15mph. Later I got out on the road and with no other cars beside or in front of me the collision warning starts beeping and flashing on the dash. There's something wrong with the **** nanny cams they've put in these cars. Their attempts to make this car safe are making it more dangerous to drive. If someone does get injured or dead, there will be no way - other than this thread - to trace it back to MB. I'm not suicidal!
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Newbie
Joined: Jan 2023
Posts: 8
Likes: 7
2020 GLC 43 AMG
FIXED! So I was right. Active Assist was the culprit here. Took my car to the dealership for a fuel tank issue and complained again about the random hesitation during acceleration. Turns out they had other C300s doing the same and they discovered that the radar sensors were picking up manhole covers in the street. This would cause the sudden cut out of power during acceleration. They reprogrammed the braking module and now I haven't had a single "oh sh*t" moment since. So a fix exists, you just need to have to programmed into the car.
I went back to all the places where this happened consistently and sure enough a manhole cover was in my path each time. It's stupid that it took this long to discover and to fix. Trying to make a care safer can often have the opposite effect.
I went back to all the places where this happened consistently and sure enough a manhole cover was in my path each time. It's stupid that it took this long to discover and to fix. Trying to make a care safer can often have the opposite effect.
Thread Starter
Junior Member
Joined: Dec 2021
Posts: 25
Likes: 14
GLC43 AMG coupe
Any updated feedback from 2023 AMG GLC 43 drivers?
Hi everyone, hope all is well.
Wondering if any of you have knowledge of whether the 2023 AMG GLC 43 coupe also has this acceleration lag issue or it was corrected?
Also wondering if the 2023 can take anything other than summer tires (the other major problem I have with my 2020 model).
Thanks!
Wondering if any of you have knowledge of whether the 2023 AMG GLC 43 coupe also has this acceleration lag issue or it was corrected?
Also wondering if the 2023 can take anything other than summer tires (the other major problem I have with my 2020 model).
Thanks!
Newbie
Joined: Sep 2021
Posts: 11
Likes: 1
AMG GLC 43 Coupe
Hi everyone, hope all is well.
Wondering if any of you have knowledge of whether the 2023 AMG GLC 43 coupe also has this acceleration lag issue or it was corrected?
Also wondering if the 2023 can take anything other than summer tires (the other major problem I have with my 2020 model).
Thanks!
Wondering if any of you have knowledge of whether the 2023 AMG GLC 43 coupe also has this acceleration lag issue or it was corrected?
Also wondering if the 2023 can take anything other than summer tires (the other major problem I have with my 2020 model).
Thanks!
Member
Joined: Jan 2021
Posts: 101
Likes: 43
GLK350 2013, GLC63S AMG
IMO the biggest issue with all of our problems discussions is that we have 0 official merc reps here around this place to chime in and actually look into investigating and fixing it. People that should be listening are deaf and disconnected,
link between regular dealerships and head office engineer teams is bad or broken altogether. The only way to make em move is a bad pr \ publicity and we cant get to be annoying enough with this forum. I wonder if we can ever
may have any real connection to some engineer like many PC hardware companies do on their forums where dev team work with end users on logging troubleshooting and rolling out fixes with updates.
Have exact same darn lag as described with glc63 as well and its bad and its not a turbo lag but a calibration \ tuning problem.
link between regular dealerships and head office engineer teams is bad or broken altogether. The only way to make em move is a bad pr \ publicity and we cant get to be annoying enough with this forum. I wonder if we can ever
may have any real connection to some engineer like many PC hardware companies do on their forums where dev team work with end users on logging troubleshooting and rolling out fixes with updates.
Have exact same darn lag as described with glc63 as well and its bad and its not a turbo lag but a calibration \ tuning problem.
Newbie
Joined: Feb 2023
Posts: 3
Likes: 1
GLC 43 AMG
If you haven't already, please do report it to the NHTSA. It only takes a few minutes:
https://www.nhtsa.gov/report-a-safet...le-information
https://www.nhtsa.gov/report-a-safet...le-information
Newbie
Joined: Feb 2023
Posts: 3
Likes: 1
GLC 43 AMG
FIXED! So I was right. Active Assist was the culprit here. Took my car to the dealership for a fuel tank issue and complained again about the random hesitation during acceleration. Turns out they had other C300s doing the same and they discovered that the radar sensors were picking up manhole covers in the street. This would cause the sudden cut out of power during acceleration. They reprogrammed the braking module and now I haven't had a single "oh sh*t" moment since. So a fix exists, you just need to have to programmed into the car.
I went back to all the places where this happened consistently and sure enough a manhole cover was in my path each time. It's stupid that it took this long to discover and to fix. Trying to make a care safer can often have the opposite effect.
I went back to all the places where this happened consistently and sure enough a manhole cover was in my path each time. It's stupid that it took this long to discover and to fix. Trying to make a care safer can often have the opposite effect.
Newbie
Joined: Nov 2023
Posts: 5
Likes: 0
From: NJ, USA
2020 GLC 43 AMG
Hi all - Just joining the team of frustrated glc owners. I am driving 2020 GLC 43 and facing the same issue day in, day out. Which led me here. Definitely feels slightly better to think its not just my car. But also infuriated that a car with this price tag manages to get us in trouble. I've been trying driving ways to avoid this, but looks like it can't be avoided. Based on some suggestions, I've reported to NHTSA & don't see a point of taking the car to dealership just to waste a day with their arrogant as**s. Gonna try out few things related to traction control & active assist to see if anything is better. But writing this today & seeing the timestamps on other posts doesn't feel anyone has got it figured out yet. Keep you all posted still.
Super Member
Joined: Oct 2020
Posts: 662
Likes: 279
From: ILLINOIS
2014 E63S
So over on the w212 e63 threads, this was a issue to plenty of guys. We recently discovered that unplugging the oil pressure solenoid enables full oil pressure all the time, giving snappier throttle response, and less lag, not to mention a safer engine. The car doesn't make full oil pressure till 2500+ rpm, so when you press the gas the delay is contributed by low oil pressures trying to switch over to full pressure, and than the downshift itself.
