Auto box hesitation?

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MattDC

Active Member
Joined
Nov 27, 2011
Messages
102
Location
Wakefield
Car
W204 C220 cdi elegance estate
I recall some posts I read that some people had had TCU firmware upgrades to rectify hesitation in their auto boxes....

This is my first MB and my first Auto so I dont really have a yardstick by which to judge whether my box is changing up correctly, having come from a manual all I can say is that at times it feels like the clutch is being released too slowly on up changes.....

Do I just book it in and ask the techs to investigate at the dealers or does anyone live close by that knows what they should drive like and advise whether its right or not! lol......
 
Is it under warranty?

Has the ATF been replaced at the correct service interval?

The updates carrie dout by main dealers are worthwhile if you have harsh up changes and down changes.
 
Its a 59 plate so is still under warranty, How often does the ATF need doing? is currently on about 36000 miles.....

The changes up and down do feel quite harsh at time and I wouldnt say that they are smooth seamless at all, is that how they are supposed to be?
 
At about 40k.

Get it booked in with MB. They will sort it under warranty.
 
On my clk you can only tell when it changes gear by the engine note and the rev counter.All mercedes should be the same ..silky smooth.
 
thats what i thought, i'll get it booked in.....

downchanges seem to be worse sometimes - with a definite jerk and then thrust as the power goes down, this can feel a bit unnerving on roundabouts when it decides it needs a lower gear halfway round.....
 
If it is only doing this when the engine is cold then they all kind of do it until they get warm....then it all gets going properly and functions quicker than manual.
 
it happens all the time not just when its cold.... I'll be calling the dealers on Monday to get it booked in.
 
Drive it like you stole it for a wee while.
 
Has it been remaped? this can give the gearbox unsmooth gear changes.
 
No idea, but it does with a few cars not just MB.
 
No, it hasnt been remapped...

Remapped correctly you shouldnt see any difference to the gearchanges, this would normally occur if using an aftermarket tuning box or a generic remap as they often do not have power curves that are as smooth as standard. Which is why you should always have a RR remap done as the mapper can then check what the delivery looks like and tweak the settings specifically for the car.

The generic map loaded onto my previous car had a nasty dip and flat spot around 2200rpm (which would give poor gear changes) which the remapper had to then remedy with a few power runs in between to check that all was well with the adjustments he made. After seeing the curve from a generic starting point map I wouldnt bother having it done again unless it was a RR custom map.
 
It can happen thats why they map the gearbox ecu at times.
 

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