Acceleration "dead spot" - AMG GLC 43 coupe
Senior Member
Joined: Dec 2019
Posts: 274
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From: Seattle, WA
2020 AMG GLC 43
I've had my 2020 GLC 43 AMG at the dealership for almost 3 weeks now for this exact same issue. No codes thrown so they can't figure out what it is. They have a case open with MB and we're at the point where we're asking for a buy back. No idea what will happen from here on out.
Thread Starter
Junior Member
Joined: Dec 2021
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GLC43 AMG coupe
Sorry to hear about that and I hope you have better luck ultimately on this than me! Mine was in for scheduled maintenance last month. I printed out parts of this thread and provided same to service manager. I was SHOCKED, shocked I tell you! when they claimed to be "unable to reproduce" the problem (as well as another obvious and reoccurring problem).
LOL so the problem is there every day for many (most? all?) of us who have this vehicle but the dealer says "no idea whatcha talkin' about".
Had to get new tires after exactly 12 months. The occasional mountain driving apparently chews up these summer tires, the only tires that fit the vehicle. Be heading back up there in a few weeks and praying there isn't much snow / ice for the summer tires to deal with.
Really like the vehicle except these 2 fatal flaws (and I hope that expression does not become literal for any of us). Interested in the Maserati electric vehicle of similar dimensions which is coming out.
LOL so the problem is there every day for many (most? all?) of us who have this vehicle but the dealer says "no idea whatcha talkin' about".
Had to get new tires after exactly 12 months. The occasional mountain driving apparently chews up these summer tires, the only tires that fit the vehicle. Be heading back up there in a few weeks and praying there isn't much snow / ice for the summer tires to deal with.
Really like the vehicle except these 2 fatal flaws (and I hope that expression does not become literal for any of us). Interested in the Maserati electric vehicle of similar dimensions which is coming out.
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Joined: Jan 2023
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2020 GLC 43 AMG
I took service manager out in the car while he filmed our drive. It happened twice. I also shared this thread with him so this is now a "community" issue. This is the only way to document this with the dealer so that they can fight with MB on your behalf. If I have to get lawyers involved - and I hope it doesn't come to that - at least I know I'm not the only person with this issue. I can't trade this car in with a clear conscience knowing how many times I've had to pucker up waiting for the acceleration to come back.
Senior Member
Joined: Dec 2019
Posts: 274
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From: Seattle, WA
2020 AMG GLC 43
By the way, I noticed you said that summer tires are the only ones that fit the vehicle. Do you have the 20" wheels, by any chance? If so, last April Michelin released an all/season tire that fits our AMG 43s. Look up the Cross Climate 2. I put them on mine and the difference in ride quality over the stock run-flats was night and day!
Newbie
Joined: Jan 2023
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2020 GLC 43 AMG
I saw the Grecale when I was in Greece a couple of weeks ago. Not sure if it's here in the U.S. yet. Good looking car. Looks a lot like the Macan in size and style. Not sure if they're still re-using MOPAR buttons or if it's got that Maserati reliability but I'd definitely take it for a spin.
Last edited by liminal; Jan 25, 2023 at 04:29 PM.
Junior Member
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Will be Glc43 in few weeks
Thanks, and sorry you experienced this. I HATE it and I swear it's going to get me into a wreck some day - you're right, that bigger picture small moment is a significant moment when other cars are coming toward you. Shame, because I like the vehicle a lot besides this issue and the baffling fact that there are only summer tires made for this car. We never stop learning - now I know that next time around I have to test for this issue and confirm the damn car can run all-season tires. ("Hey MB dealer, I'm getting rid of the Maserati coupe because I'll be driving in snow up on a mountain...wait, this GLC43 only has summer tires available? Really, like literally nothing else exists? Well, no thanks, I need a different car.")
OF COURSE there are winter tyres for it.
in Europe on the certification card of any glc43 (homologation) you find M+S in a smaller size than 285 rear and 255 front, is is like 245 front AND rear. However I found a complete set of glc AMG wheels in 20inches with winter tyres 285 rear and 255 front.
Good luck
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Joined: Jan 2023
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2020 GLC 43 AMG
Sooo, the dealership isn't denying a problem but they said since they don't have any errors or codes being thrown, they didn't know what to fix. They said I would have to contact consumer affairs which I have done and I now have a case open with them. They are reaching out to the dealership to research the issue and will make a determination from there. I have requested the case number ID for the case opened with MB by the dealership, but have not heard back as of this post. If you want to be added to the consumer affairs issue, please DM you contact info and last 8 of your VIN. I will be calling them tomorrow for an update.
I don't feel comfortable having my wife drive this car as she already shot out into an intersection after the light changed red because she didn't understand what was happening with the acceleration until after the light changed. I was yelling at her because I thought she just wasn't paying attention. She's freaking out because she's got multiple cars honking at her. Had it been a second longer she may have hit someone or been hit. I thought this was only during a turn into traffic or when a median is involved. Thought it was a camera, collision avoidance system panic but this was from a standstill at an intersection with my wife who is beyond conservative in her driving habits. The dealership reported that they saw this twice - car simply didn't go at a green light - in the first week they had the car.
I don't feel comfortable having my wife drive this car as she already shot out into an intersection after the light changed red because she didn't understand what was happening with the acceleration until after the light changed. I was yelling at her because I thought she just wasn't paying attention. She's freaking out because she's got multiple cars honking at her. Had it been a second longer she may have hit someone or been hit. I thought this was only during a turn into traffic or when a median is involved. Thought it was a camera, collision avoidance system panic but this was from a standstill at an intersection with my wife who is beyond conservative in her driving habits. The dealership reported that they saw this twice - car simply didn't go at a green light - in the first week they had the car.
Member
Joined: Jan 2021
Posts: 101
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GLK350 2013, GLC63S AMG
2021 63s owner here, have car since new and my wife drives it mostly. Car experiences this dead spot hesitation pretty much every 2nd time when its coasting at low speeds and off the throttle, decelerating b4 some maneuver like lane change or letting someone get into your lane or crossing intersection and then you need to accelerate and it just does nothing for 1-2 sec. Its very annoying problem and quite a safety concern. The lower the coasting speed the more pronounced this lag could be, its especially bad at low speeds like 5-10 mph. Happens in all modes. Looks like firmware / calibration glitch or some miscommunication/misunderstanding between those ecu tcm cpc modules. At the beginning i was pretty sure its hunting for proper gear but then ive noticed that most of the times it stays in same 2nd gear and worst delays are usually happen with 2nd. Ive also noticed pretty bad jerking or shivering at higher 4-8 gears and low rpms low load uphill acceleration under 2.5k rpms when car is cold for like first 10 min of driving, not sure if it is engine or tranny issue, disappears when fluids reach like half of their working temps, not sure if its a mechanical glitch or a feature but while it jerks it feels like something is broken.. The only way to avoid this dead spot more or less predictably is to preselect gear manually and start maneuver while in manual mode, not really what we expected from something with AMG sticker and price tag on it. I made a complain with dealership and they said we can't find any problems, no errors and all the firmware is up to date.
I think it would be more effective if each of the owners with this issue will contact mb individually so please post this case id for us to refer to.
I think it would be more effective if each of the owners with this issue will contact mb individually so please post this case id for us to refer to.
Last edited by Serge81; Feb 1, 2023 at 02:06 PM.
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GLK350 2013, GLC63S AMG
Had some city driving around yesterday and been counting dead spots just for fun. In 2 hrs I had 18 of which 3-4 were really bad. Like you give it 30-40% of the pedal to jump in some gap and it just bogs down and you are out of your time frame. Ive noticed if you give it very light throttle it almost never has this dead spot but this kind of acceleration is not applicable to most road scenarios and situations. So most common one to get this happen is a low 5-10 mph rolling off the throttle dropping speed preparing to cross the intersection or main road or make a sharp turn and then ask for good accel and thats when tranny usually is in 2nd gear and its not optimal to give you 1st, it bogs then think a bit and then makes whaaa in that same 2nd gear. Please share your experience, im sure pretty much every facelift car with this 9sp tranny has this problem, i tried glc43 the other day and it behaves very close while c43 4matic didnt have it at all.
Junior Member
Joined: Dec 2021
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C300
Shift Lag response
I'm going to say this is normal. Any of the 43's I've driven have a lot of lag especially when trying to suddenly accelerate from a slowing roll. It feels like the transmission deciding which gear it wants, coupled with Turbo lag, then add in the normally soft pedal response. Hopefully a GLC43 owner will chime in.
Yeah it's apparently normal... Mine does it too... Especially in comfort mode...
Newbie
Joined: Jan 2023
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2020 GLC 43 AMG
It's definitely not turbo lag, it's like the engine and transmission simultaneously shut down for 1-2 seconds. Sometimes it throws my head forward if I already have momentum built. Definitely a bug, not a feature.
Newbie
Joined: Sep 2021
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AMG GLC 43 Coupe
I only have this issue when I’m in Eco mode. In Comfort and especially Sport+, I can rip from behind anyone and disappear into the night.
In Eco mode however, I feel like I would definitely end up in a cemetery with how long it takes, but that’s due to me not training my ride to drive fast in Eco.
In Eco mode however, I feel like I would definitely end up in a cemetery with how long it takes, but that’s due to me not training my ride to drive fast in Eco.
Senior Member
Joined: Dec 2019
Posts: 274
Likes: 76
From: Seattle, WA
2020 AMG GLC 43
I only have this issue when I’m in Eco mode. In Comfort and especially Sport+, I can rip from behind anyone and disappear into the night.
In Eco mode however, I feel like I would definitely end up in a cemetery with how long it takes, but that’s due to me not training my ride to drive fast in Eco.
In Eco mode however, I feel like I would definitely end up in a cemetery with how long it takes, but that’s due to me not training my ride to drive fast in Eco.
Super Member
Joined: Sep 2015
Posts: 725
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From: Chicago area
2015 E400 and 2015 GLK350
Well. . . all of you seem to think this problem is specific to the 43's and the more recent model years. . . NOT BY A LONG SHOT!
I have a 2015 E400 (3.0l TT V6), and have had this exact problem since day 1 with the car. It has been to the dealer many times, with the usual response "Working as designed." Or "Could not replicate."
I find that often when the car goes "to sleep" I get quicker response if I totally let off the throttle, then step on it again. Sometimes I just "rolling brake-torque" it and let the hardware bear the brunt of my frustration.
Part of this issue is the "drive by wire" throttle implementation. I believe this because we also have a GLK350, same model year, no turbo, and it sometimes stumbles, but only very slightly. It seems that the turbo, and vehicle-specific programming exacerbates this issue immensely. It is probably worse on the higher-performance varieties of the cars, too.
I have a 2015 E400 (3.0l TT V6), and have had this exact problem since day 1 with the car. It has been to the dealer many times, with the usual response "Working as designed." Or "Could not replicate."
I find that often when the car goes "to sleep" I get quicker response if I totally let off the throttle, then step on it again. Sometimes I just "rolling brake-torque" it and let the hardware bear the brunt of my frustration.
Part of this issue is the "drive by wire" throttle implementation. I believe this because we also have a GLK350, same model year, no turbo, and it sometimes stumbles, but only very slightly. It seems that the turbo, and vehicle-specific programming exacerbates this issue immensely. It is probably worse on the higher-performance varieties of the cars, too.
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If it has to do with the transmission not knowing what gear to go to, or if the transmission's delayed response is the main cause and not really the turbo as someone mentioned, it might be worth trying to reset the transmission adaptations via Xentry.
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2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
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!
you can add a sprintbooster
These can possibly help
https://mbworld.org/forums/w212-amg/...-annoying.html
An Ecu and tcu tune can also help
Last edited by PeterUbers; Mar 14, 2023 at 03:55 PM.
Member
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GLK350 2013, GLC63S AMG
Member
Joined: Jan 2021
Posts: 101
Likes: 43
GLK350 2013, GLC63S AMG
you can try resetting the tcu
you can add a sprintbooster
These can help significantly
https://mbworld.org/forums/w212-amg/...-annoying.html
you can add a sprintbooster
These can help significantly
https://mbworld.org/forums/w212-amg/...-annoying.html
Out Of Control!!
Joined: Jun 2004
Posts: 13,799
Likes: 3,229
2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
Last edited by PeterUbers; Mar 14, 2023 at 04:06 PM.
Out Of Control!!
Joined: Jun 2004
Posts: 13,799
Likes: 3,229
2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
Member
Joined: Jan 2021
Posts: 101
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GLK350 2013, GLC63S AMG
Older cars had just 1 dbw pedal map, these new ones have s+ / racing modes with jerky pedal mapping that acts like booster. Again, this particular car dead spot isnt connected to lack of pedal input and playing with it does nothing to help.
Out Of Control!!
Joined: Jun 2004
Posts: 13,799
Likes: 3,229
2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
whats your experience in your newer cars?
