W202 transmission reset.

[tron]

The 722.6 5 speed automatic is adaptive and if you buy one that has been used by the archetypal little old lady, it will be in top somewhere around walking pace. This means that if you kickdown, the shift is lazy and it goes from fifth to fourth without arriving anywhere near a useful point in the torque curve.
A transmission reset is a jolly good idea and it transforms the car. I know, I just did it.
For those who don't know how to do it, it goes like this:
Everything off.
Key to second position. Do not start the engine. Depress accelerator pedal fully to kickdown and hold it for fifteen seconds. release the pedal and switch off.
Wait for three minutes without operating anything. Don't open the doors or operate the interior lights, radio or anything else.
After three minutes, the transmission is reset. The next time you drive it, it will adapt in accordance with the first forty shifts. If you glide along climbing up through the gears and backing off, you will get economy at the expense of performance. Use a little thuggery and you will have it set up to pull away much more strongly and the kickdown will be faster and you will end up with a good bit more go. My 250TD now behaves as though it has a T!

 

[jazzyglobe]

I have tried this method and when I did it, it seemed like it worked.

I recently figured out how to do a reset procedure through my OBD reader. Since, then gear changes have been very smooth indeed.

 

[Iceash]

Is this not a placebo affect?

 

[tron]

Certainly not.

 

[Iceash]

Other than feeling different how can it be tested?

I know in the past when resetting throttle position sensors they go through learning phase which is rather odd while it learns for a few miles.

Just curious as when I tried it earlier it didn't seem to make a difference.

 

[tron]

By driving it. Perhaps yours is calibrated to your driving style. Mine was not calibrated to mine and I have enough experience to know the difference. If the shifts come in at 3000 rather than 1500 RPM on a Turbodiesel, it is noticeable.
The engine makes itself heard, and the ASR has, at last, been felt to work because it is producing some TORQUE! The shift is less muddy and I get up to speed much faster (and therefore can lift off earlier.)

 

[Iceash]

Cool,

I'll try it again. Only had the car a week lol. Is this info in the manual?

 

[tron]

No. That is why I posted it. It does appear in MB's technical manual afaik. Check your documentation and ensure that you have the 722.6 trans.
Source club 202/maintainance.

 

[Giantvanman]

Please excuse my ignorance here. Are we saying that having had the first forty gear changes (which basically being driven off the line, parked, moved to transporter etc etc) then the gearbox is set unless it is reset? If so I was mistaken in my belief that it re-learned as it went, adapting to the driving style which is why if you suddenly go into say eco drive mode, it feels strange because you spent the previous drive foot to floor.

 

[IanMSpencer]

Please excuse my ignorance here. Are we saying that having had the first forty gear changes (which basically being driven off the line, parked, moved to transporter etc etc) then the gearbox is set unless it is reset? If so I was mistaken in my belief that it re-learned as it went, adapting to the driving style which is why if you suddenly go into say eco drive mode, it feels strange because you spent the previous drive foot to floor.

The clue is in adaptive, yes it does relearn and reasonably quickly. Assuming that was the gearbox in my C240 W202, it would go off to sleep on a dawdle behind lorries on a leisurely drive so it needed to be woken up to do a change, manually overriding was safest. A couple of kickdowns and some hard acceleration was enough to wake it up and change the feel.

Also, the gearbox works differently when cold, where it will hold low gears until the engine has warmed.

A reset should not be necessary, but who knows what glitches the software has. Also, it is quite possible that someone's usual driving style sets it into granny mode, they then reset and drive with enthusiasm, and then wonder why they next think about it that it is back to granny mode. Remember, that the gearbox tries to work out the optimum gear and what might feel pacey and exciting using lower gears may get the same result using the torque in higher gears.

If you've driven a few miles and the gearbox hasn't adapted to heavy acceleration by offering later change-ups, it suggests something isn't quite right somewhere.

 

[andy27168]

I am not in any way disputing the reset laid out above (though it did,nt do anything noticeable on my 202 AMG 722.6 box) but has been said, you can gain the same difference just by gunning it away from a few junctions.
As soon as you slow down and are in traffic for a few miles it will be right back where you were before you reset it.
There was a thread on here a few years ago where this was discussed, IIRC tempers got somewhat frayed.

 

[Laters]

Not wanting to argue with anyone but I thought the above procedure was the reset procedure for the drive by wire throttle and not the gearbox.

resetting the 7G-Tronic gearbox auto learning. - MBWorld.org Forums

 

[KeithJG]

All ECU computerised motors are adaptive or learning....

They usually learn over a period of time and not just two or three traffic light starts.....it has to adapt to the drivers habits.

On my Volvo`s where you could remove the battery completely with no detriment to any electricals all the settings would be lost and the learning phase restarted and it took a couple of days to get back as it were, so to speak. Even change of fuel ron alters the drivabilty and it learns...

One thing i don`t understand with Merc owners is them complaining about the slight stutter while in C mode on quick throttle application......surely the mode should be treated as the mode stands for which is Comfort Mode so the engine and box is treated as such with lighter slower movements of throttle etc.

If one wants sit up and go instantly then use S Mode as Mercedes say in the owners manual.....they actually say this should be the normal mode to be in!


As above ^^^^^^this reset should be for fly by wire setting......the box and engine should adapt without reset.....as it says in the Link just drive it hard if you want to change the response profile.

It should feel different as the throttle position has been reset!