- Mercedes-Benz C-Class and C-Class AMG: How to Reset ECU and TCU
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resetting the 7G-Tronic gearbox auto learning.




Heres my experience with it.
The car was very smooth and changes at about 2000 revs lightfoot.
I recently took it for 20 000Km service, where upgrade was performed and L5 sensor replaced. Receiving the car it flies and changes roughtly in Comfort mode ref freely over 3000-4000 revs lightfoot in C.
Feels like S-mode without stiffness in suspension.
I then reset it:
1-Swith on.
2-Put foot hard on accelarator for 10 secs.
3-switch off, leaft key in ignition.
4-release foot from accellerator.
5-wait 5 min.
Now here comes the trick:It was fast and rough, I want it slow and smooth in C-Mode. For fast I use S-mode.
6-I then reverse out of garage, nothing noted.
7-Then I accellerate lightfoot forward down the road.
>The car then refs freely above 2000, but just after 2000 refs I lift foot completely off acellerator, it felt something happend.
8-Then I accelerate further to 2nd gear, after which it changed at 2000RPM from 1st, 2nd gear same thing, I release accelerator immediately after 2000 RPM.
9-Guess what, the car quickly learned, and was super smooth again in all gears in C- mode after that.
This all happened within 1 KM from home.
So it looks the 1st two gears are of significant importance initially after the reset.
Result. Driven 100Km so far no problem.
C-Mode super smooth as it should be and S-Mode fast as that should be.
Now this is for me and how I like it.
NOTE:I actually thought something was wrong with the car.

S & C buttons have zero effect on suspension. If you have advanced agility control you have a separate SPORT button. I understand that AAC is not available in the US?




I do have the Advanced Agility Control option, pad R18 000 for it.
Whatever I managed to "RESET" it made a clear noticible difference.
If I want it fast I just use S-mode, it remenmbers it in that catagorie.
Last edited by Moto_Guzzi; Sep 14, 2009 at 02:55 AM.








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Correct procedure for throttle reset; Which is pretty much what you did. And yes it does make a clear and noticeable difference
1. Turn the ignition key to the on (not start) position.
2. Press the gas pedal to the floor and hold for five seconds.
3. Turn the key to the "off" position (don't remove the key), then release the gas pedal.
4. Wait at least two minutes for ECU to reset.
Last edited by Glyn M Ruck; Sep 14, 2009 at 05:30 AM.
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1. Turn the ignition key to the on (not start) position.
2. Press the gas pedal to the floor and hold for five seconds.
3. Turn the key to the "off" position (don't remove the key), then release the gas pedal.
4. Wait at least two minutes for ECU to reset.[/QUOTE]
Glyn, Does this proceedure hold for the 5 speed box on the 220CDI ?




For me I chose the slow, cause it fits perfectly with the suspension in Comfort Mode....Floor it in Sport Mode, where susprention is stiff.
https://mbworld.org/forums/new-s-cla...n-shifts.html?
I wonder if the TSBs noted there apply to the W204?
My 2009 C3004M has the initial cold start 2-3 jerky shift issue - the very first 2-3 shift off a cold engine start is jerky, then its fine.

It does not apply to diesel engines.
It does not apply to diesel engines.
https://mbworld.org/forums/new-s-cla...n-shifts.html?
I wonder if the TSBs noted there apply to the W204?
My 2009 C3004M has the initial cold start 2-3 jerky shift issue - the very first 2-3 shift off a cold engine start is jerky, then its fine.
Correct procedure for throttle reset; Which is pretty much what you did. And yes it does make a clear and noticeable difference
1. Turn the ignition key to the on (not start) position.
2. Press the gas pedal to the floor and hold for five seconds.
3. Turn the key to the "off" position (don't remove the key), then release the gas pedal.
4. Wait at least two minutes for ECU to reset.





