Adaptive transmission

disneysw · #1 10-23-2006, 03:23 PM

I read that the adaptive transmission 'learns' your driving style and uses the info to select the correct gear - can it be reset or how long does it take to re-learn when your style changes?

Mine sometimes is slow to accelerate from a complete stop when I sink-the-boot. About one second later the car takes off! At all other speeds the car is fine.

(DonC if you read this is sounds like your issue)

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noncom23 · #2 10-23-2006, 03:34 PM

Have you had a tranny software upgrade?

noncom23 · #3 10-23-2006, 03:36 PM

Try turning off engine. Switch key to first click and hold for ten seconds. Switch back off and restart. Then test drive.

Don Coffey · #4 10-23-2006, 04:17 PM

Quote:

Originally Posted by disneysw

I read that the adaptive transmission 'learns' your driving style and uses the info to select the correct gear - can it be reset or how long does it take to re-learn when your style changes?

Mine sometimes is slow to accelerate from a complete stop when I sink-the-boot. About one second later the car takes off! At all other speeds the car is fine.

(DonC if you read this is sounds like your issue)

Disney, your on the money there, this is along the same lines as the problem I have. Do you have the diesel engine? The reason I ask is because according the BMW GB's technical guru, then it's the way the transmission is programed. Believe it or not, the transmission will not go down the gears as you slow, but instead wait until you come to a complete stop! So if slowing for a give way and you see a gap, when pushing on the throttle, you have to wait as the transmission suddenly wakes up to the fact that it is in the wrong gear and has to change.

So much for the 'Ultimate Driving Machine'

Don

LVR · #5 10-23-2006, 07:48 PM

When you drive, the driving style is 'learned' by the software and each time you move off from stop, it applies this knowledge against set values.

Measurements particularly crucial are the throttle pressure and speed of depression from stop. For economy reasons, start off is usually in 2nd gear as otherwise stop/start traffic would be horrendous.

If, on the other hand the trans detects greater pressure/speed of throttle depression, it selects a different set of values (gear shift points) and selects a more aggressive mode, meaning it will select 1st gear.

The four main modes are Extreme economy, Economy, Sport and Extreme Sport. Sport is selectable manually by moving the trans lever into S and XS is when you use the manual trans. There is also a Hill climb/descent mode and towing settings.

The problem seems to be in the fact that there is so many values and decisions that the computer must measure/compare that the time taken (typically 0.75 of a second) impacts on the drivers' sense of motion/driveability as a jerk/slam/delay as you are still pressing the accelerator whilst it is thinking.

Check for a software update as they have been refining these responses, but the reality is that it is all down to your driving style. Drive conservatively and you will eventually end up driving around in top gears all the time. It is a deliberate (and regrettable) feature of BMW economy requirements for their marketing.

As an aside, my wife has a very heavy driving style from the lights. She just plants the foot and goes, whereas I tend to be more conservative. Consequently when I jump into her 3.0, it fairly leaps off the line all the time.......

AzNMpower32 · #6 10-23-2006, 10:15 PM

Someone needs to put this article on the front page of X3World/X5world.....

http://www.x3world.com/attachments/x...f?d=1154638490

The delay or lag in off-the-line is usually attributed to the 2-1 downshift when the computer suddenly realizes you want to go faster. It determines this mainly by vehicle speed, throttle, and how fast you push the gas pedal down. By default in normal mode, many BMWs (my X3 excluded) start from 2nd gear from a stop, but when you want to go faster, it changes to 1st. That is what causes the delay.

Believe it or not, but I've experienced all 4 shift maps, so I know they're there! XS is really cool.......no upshifts whatsoever when you let off.

disneysw · #7 10-24-2006, 02:31 AM

Is there someway to know which mode the car is in?

DC - yes I have the diesel engine and it is really only a problem on round-abouts (rotarys). I am going to try the 'reset' method outlined above to see if it makes a difference. Otherwise I guess the auto-box needs a sports mode :-)

noncom23 · #8 10-24-2006, 10:20 AM

Quote:

Originally Posted by disneysw

Is there someway to know which mode the car is in?

DC - yes I have the diesel engine and it is really only a problem on round-abouts (rotarys). I am going to try the 'reset' method outlined above to see if it makes a difference. Otherwise I guess the auto-box needs a sports mode :-)

Any results?

disneysw · #9 10-24-2006, 04:59 PM

Can't say I have noticed any difference. It may be because I spend most of my commute in rush hour traffic and then get a brief burst of 'freedom' on a ring road which includes a number of round-abouts.

Of course it would help to know what mode the car was actually in.

noncom23 · #10 10-24-2006, 05:21 PM

yeah, would have been nice to have a swtch or LED, to know what you are running in. Outside of sport, of course.

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