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Discussion Starter #1
Hi All,

I made a previous post about a year ago regarding a transmission issue with my 2016 GLA 45. To recap, this transmission issue happens when I'm traveling on the highway around 80KM/H (50mph) - 100KM/H (60mph). In comfort mode, the gear should be either in 6 or the 7th. The problem occurs when I step on the accelerator to about half way to over take someone. The gear drops, revs up to about 2500rpm - 3000rpm and then a sudden jolt while the transmission disengages and reengages within a second. To make it relatable, it seems like you stalled a car if you are driving a manual. But this time, I heard the tires squeal like a drifting noise which means the problems have been getting worse. I can't duplicate the problem all the time but when it happens it makes your heart skip a beat.

Anyways, I brought in the car to the dealership for the 3rd time for this issue and they just can't seem to find anything wrong with it. Mechanically everything seems to be perfect. The dealer said they'll escalate this issue and have all the transmission data analyzed and see if any anomaly pops up.



My question is, has anyone else run into this problem or am I the one off? Didn't have the greatest of luck with this car from the start but I love it and adore it.:crying:



Thanks for reading! :)
 

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I looked at your original post for reference:

https://www.glaowners.com/forum/mercedes-benz-gla45-amg-forum/26452-2016-gla-45-transmission-problems.html

Here's a process that has been successful for some of our members when gremlins hit and dealer service could find no issue, resetting the transmission. I don't know if that's the case for you or not, but it could be worth a try:

https://www.glaowners.com/forum/engine-technical-discussion/23817-reset-transmission-adaptive-learning-padel-travel.html
 

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Discussion Starter #3
Hey Turbolink,

Unfortunately that method did not work :( The dealership tried to reset the transmission "computer" but it didn't seem to have fixed the issue. But then again, they might not have done it so I will test it out when I receive the car back! Thanks for the tip! I did not know we could do that ourselves. Always thought that was best left for the mechanics.


Cheers
 

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sometime it just because of earthing issue. have this on my fiat selespeed. i know it different car make. but who knows it might help


Sent from my vivo 1723 using Tapatalk
 

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then a sudden jolt while the transmission disengages and reengages within a second.
But this time, I heard the tires squeal like a drifting noise which means the problems have been getting worse. I can't duplicate the problem all the time but when it happens it makes your heart skip a beat.




Thanks for reading! :)
First time I saw a reference to a DCT, I had to educate myself of this neato sounding Idea

This is the first car I've owned by choice without a full set of pedals, so take this with a grain of salt

OP's description made me think that both clutches are engaging at the same time. That would lock the output shaft

how, why, etc ...... No clue
 

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Hey sheaa,

That does sound similar to my experience although your seems to be worse than my situation. I have been in contact with the dealer and so far they have yet to find any codes or errors. It's been escalated to the regional service manager to diagnose or try to find what is causing the problem.



To give an update to what's happened so far, to no surprise the dealer couldn't recreate the issue. It's such a uncommon issue that I don't blame them. But what I do find infuriating is their way of "remedying" this issue. I have been given really weird remedies that they say would help but when I confront them about it, they try to avoid answering my question.


I just want to know what's wrong with the car and how it can be fixed :( I just want to drive it and enjoy it without having to worry about any issues :(
 

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Discussion Starter #8
I experienced something similar. For me it felt like the manual transmission days when you pop the clutch during acceleration. Mine eventually went to transmission safe mode, and had to restart the car to reset. It was a faulty crank sensor and the dealer found error code from the sensor.

I had a thread open when I first had the issue. Hope it helps.

https://www.glaowners.com/forum/mercedes-benz-gla45-amg-forum/27118-fuel-cut-middle-rev-range.html
Hey sheaa,

Just read your forum. Should have read the entire thing before I answered haha woops :D

When you say your experienced a jolt like a transmission slip, that's exactly what I felt. Oddly enough, it only happens to me once and doesn't even go into limp mode or anything, just carries on normally. Maybe I just don't drive it hard enough for it to go into limp mode :|. But I'm glad that someone else has experienced this issue and I will try to bring it up to the dealership if they really can't find anything.


Thanks for replying!

Cheers
 

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If MB is like a VW I had the car tries to be prepared for the next shift based on how you are driving. If if see you are slowing down it will get the next lower gear read to kick in so the shift will be smooth. If you are slowing down and it is reads to shift to the lower gear and then you hit the gas then as it is down shifting it moves back to the higher gear that could possible be what happened. The trans is a standard trans and not an auto that has bands and so forth. The odd gears on one shaft and even gears on a second shaft there are two clutches one for each shaft. Just what I saw with the VW I had and MB might work the same way.
 

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If MB is like a VW I had the car tries to be prepared for the next shift based on how you are driving. If if see you are slowing down it will get the next lower gear read to kick in so the shift will be smooth. If you are slowing down and it is reads to shift to the lower gear and then you hit the gas then as it is down shifting it moves back to the higher gear that could possible be what happened. The trans is a standard trans and not an auto that has bands and so forth. The odd gears on one shaft and even gears on a second shaft there are two clutches one for each shaft. Just what I saw with the VW I had and MB might work the same way.
Good points. On my Porsche 997.2 with PDK I can fool the car and the transmission acts very poorly. But that is my fault.

The DCT (or PDK in the Porsche world) is not an automatic transmission and thought is required on how you are driving.
 

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Hi Breitling,

Here is my story and for those who has similar issues.

When my car was in hard acceleration I got a jolt, this was when my car was about 45000km, I didnt really think of it as a huge problem since which one of us are flooring it every day? now my car is 90000km, I am on my 3rd rear differential (all covered by warranty) and they finally figured out the problem was crankshaft sensor. this last repair i went in for was when my jolt was intense as ****. i was accelerating on the highway going from 90km aiming to reach 130+, almost floored the gas and i got 3 jolts that put my transmission into 7th gear and locked there (maybe a safety mode?). i was not able to change gears or any modes, nothing worked. i had to press on the gas and slide to the side. got my car towed to MB, they ran the codes and got an error ..finally.

After changing crankshaft sensor, the car is feeling new. It also fixed another problem that some ppl felt, which was that accelerating from stops/red light felt like mini launches. I think this was also the problem from sensor sending wrong information, which ultimately caused to breaking rear differential.

soo...i highly suggest to look into that sensor.. luckily my car is in extended warranty. these repairs would have costed a fortune..
 

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Hi Michael,

Thanks for sharing your experience and story! Yeah, what you experienced seems like my issue. Although one thing that is different is that my car never went into a "safety" mode. Probably because I eased off a bit and gave the car a bit of time to catch up or fix itself.

Of course when I try to recreate the issue, it never happens nor does a code show up haha.

I will definitely look into the sensor. The dealership has escalated this issue to the Regional Service Manager so I am hoping to hear back within the next week. Let's hope for the best and they figure out what the issue might be so this issue can be easily fixed for other people who experience it.


Cheers!
 

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Watching this thread... I mentioned in the other thread that our '16 GLA45 was a manufacturer buyback, due to transmission issues. We never learned what the specific issue was but since we bought it 2 years ago following the repair, the transmission has been flawless. 13.5k miles on the clock now... let's hope it stays good.
 

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Just wanted to give a quick update with the 2016 GLA45.

I just picked up the car this morning and the managers and mechanics have no idea what the problem is. They have cleared the car and said nothing is wrong with it. I have asked if there were any errors in the data I asked them to analyze or if any sensors were reading wrong but they said everything is working fine. I can't really say anything else if nothing is really wrong haha.

I will try to reset the ECU/TCU before my travels tomorrow and see if that helps with anything. I'm still puzzled by what could be causing the issue but let's hope for the best.


Thanks for all the input!

Cheers
 
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