Unresponsive E270Cdi - Solved

marko

New Member
Joined
Dec 22, 2003
Messages
8
Some of you may remember about this time last year I posted about an E270Cdi that was about as smooth and responsive as a tractor.

We've solved the problem - well, found the cause anyhow.

Mercedes, in their infinite wisdom, appear to have fitted an "intelligent" "adaptive" drivetrain, that changes to suit your driving style.

With morning commute speeds ranging from zero to 60km/h, the car has decided not to bother responding to the accelerator pedal until one second has elapsed, and not kicking down 1 gear until at least 3 seconds have elapsed, never kickign down two gears and always changing up by 3750rpm.

We've not long been out in the bush in Botswana in a 110 Land-Rover, but the drive from Joburg to Botswana and back is 2500kms of long straight road @160km/h with the odd slam on the brakes for the kamikaze donkey/cow and nail it away from said grumpy cow with horns ASAP. The car appeared to become more responsive through the journey. We then went to the Blyde River Canyon (reccommended - v. nice!) - lots of hills and bends. I gave up letting the autobox think for itself, as by the time the damned thing kicked down it was neccessary to kick down 2 gears to get up the hills. Took to locking it in '1', '2' or '3', aiming to cruise @3000rpm and never letting it drop below 2250rpm. Also used the limiter rather than cruise, and held right foot flat on the floor. Got a whopping 18mpg out of it - BUT the car is transformed - it now holds gears to 3500rpm normally, 4250rpmish when accelerating hard, kicks down of its own accord and the lag on the throttle pedal is reduced to about 0.5 seconds. Its still rubbish, but at least rubbish on par with a Land-Rover rather than a Tractor. Fuel economy is also better, as one can drive smoothly rather than pressing the throttle, pressing the throttle more, pressing the throttle even more then leaping off the lights in full kickdown. (Now 30mpg@130km/h cruise)

Other, more sensible, car manufacturers fit a sports/economy switch, or just have a fixed throttle response and gear change pattern that the driver can get used to...

Question is - can the "adaptiveness" be turned off - ie, can the car be 'locked' in its current state, or will it revert back to the prior unresponsive state? You can change headlamp delays, ambient lighting, 97 way aircon - but changing the 'box would be nice!
 

watsone91

Active Member
Joined
May 8, 2004
Messages
65
Location
scotland
Car
c250tdi/e200
Fuzzy logic when you first got the car you treated it with respect it learned this and so it will need teaching new tricks
 

marcos

MB Enthusiast
Joined
Oct 6, 2003
Messages
1,313
Location
Hertfordshire
Car
C43 estate
The gearbox should not behave as youve described because it is adaptive. I think you may have a serious problem with the gearbox, it learns your style but will still be responsive when you want it to be.
 

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