Clunky shifting after TCU update
Thread Starter
Member
Joined: Sep 2018
Posts: 112
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From: Texas
E63s AMG
Clunky shifting after TCU update
2018 E63
A few months back I had the rear main seal replaced at the dealer. I was told they updated the TCU (Transmission Control Module). I need to confirm what the update was for. Since the update, the shifts are less crisp and clunky on the 2-1 downshift. I don't expect torque converter smooth, but this update seems to be a downgrade. Incidentally, I had a trans service performed at the same time.
Have any of you experienced this? Perhaps I need to put the trans in relearn or maybe flash it back a version.
A few months back I had the rear main seal replaced at the dealer. I was told they updated the TCU (Transmission Control Module). I need to confirm what the update was for. Since the update, the shifts are less crisp and clunky on the 2-1 downshift. I don't expect torque converter smooth, but this update seems to be a downgrade. Incidentally, I had a trans service performed at the same time.
Have any of you experienced this? Perhaps I need to put the trans in relearn or maybe flash it back a version.
Out Of Control!!
Joined: Jun 2004
Posts: 13,799
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2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
2018 E63
A few months back I had the rear main seal replaced at the dealer. I was told they updated the TCU (Transmission Control Module). I need to confirm what the update was for. Since the update, the shifts are less crisp and clunky on the 2-1 downshift. I don't expect torque converter smooth, but this update seems to be a downgrade. Incidentally, I had a trans service performed at the same time.
Have any of you experienced this? Perhaps I need to put the trans in relearn or maybe flash it back a version.
A few months back I had the rear main seal replaced at the dealer. I was told they updated the TCU (Transmission Control Module). I need to confirm what the update was for. Since the update, the shifts are less crisp and clunky on the 2-1 downshift. I don't expect torque converter smooth, but this update seems to be a downgrade. Incidentally, I had a trans service performed at the same time.
Have any of you experienced this? Perhaps I need to put the trans in relearn or maybe flash it back a version.
how often have you driven the car since the tcu update? It takes a couple hundred miles to adapt; you can also re adapt it with the "pedal dance" procedure and give it another couple
hundred miles.
did you have them re check the trans fluid level? These cars can shift weird if the level is slightly lower than topped off. Dealer did this work - used the correct fluid I presume
also did you add your case to the RMS fail thread?
https://mbworld.org/forums/w213-amg/...fail-club.html
you would need someone like Benzninja to revert the tcu update a dealer applied but it's unclear what's causing your clunking so far
Last edited by PeterUbers; Sep 8, 2025 at 12:14 AM.
Thread Starter
Member
Joined: Sep 2018
Posts: 112
Likes: 58
From: Texas
E63s AMG
Thanks for the detailed reply! Almost 60k. Trans fluid changed around 25k and 58k. I've driven it a few thousand since the update.
yes, I am in the RMS db. I am having my oil changed on Tuesday at a new independent shop that specializes in Benz. They have a good rep, so I will ask them to check the fluid level. They may be able to flash the TCU.
Can you detail the "petal dance"?
yes, I am in the RMS db. I am having my oil changed on Tuesday at a new independent shop that specializes in Benz. They have a good rep, so I will ask them to check the fluid level. They may be able to flash the TCU.
Can you detail the "petal dance"?
Out Of Control!!
Joined: Jun 2004
Posts: 13,799
Likes: 3,228
2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
Thanks for the detailed reply! Almost 60k. Trans fluid changed around 25k and 58k. I've driven it a few thousand since the update.
yes, I am in the RMS db. I am having my oil changed on Tuesday at a new independent shop that specializes in Benz. They have a good rep, so I will ask them to check the fluid level. They may be able to flash the TCU.
Can you detail the "petal dance"?
yes, I am in the RMS db. I am having my oil changed on Tuesday at a new independent shop that specializes in Benz. They have a good rep, so I will ask them to check the fluid level. They may be able to flash the TCU.
Can you detail the "petal dance"?
Out Of Control!!
Joined: Nov 2018
Posts: 11,409
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From: San Francisco Bay Area
2019 C63CS
2-1 downshift while still moving? It shouldn't do that in the first place once properly adapted. I have a C63, but same transmission. Mine did the 2-1 downshift initially, until it properly adapted to city driving and hasn't done it since. Now it stays in 2nd until I come to a full stop and then engages 1st while the car is stationary. If I do a California stop, it stays in 2nd. I've also driven a bunch of other AMGs with the 9-MCT since then, including the E63 and none of them downshifted to 1st coming to a stop while still moving, but they were all past the break-in and the transmission was fully adapted. So, if they updated your TCU, yours may have gone back to factory settings, and you need to let it do the whole adaptation cycle again.
Last edited by superswiss; Sep 8, 2025 at 01:45 AM.
