Brakes sometimes act strangely (Kick back at full stop)

[TheKingSim0n]

Originally Posted by jst2878

i would reset the transmission. Its a simple operation you can do if I knew where it was on this site. Use your key and press the gas pedal around 30 seconds is part of the procedure. would be good to do so You can erase the past drivers style. could help but it might be the rear transfer case belt which gets loose over time. what year is yours. if its 2004 or newer than it could be a software update by bmw

I believe your referring to

- turn key to position II
- press gas pedal all the way to the floor, past the 'click'
- hold like this for ~ 30 seconds
- lift foot off gas pedal
- turn key all the way to the right (i.e. start car)
- drive forward

?

If so, Yes it does work but only for a few times, after i used to try it, the 4th time or so it just didn't seem like it had any more effect on the hard down shift issues I usually get after driving for an hour or two.

I'm not to worried about it though, I am planning on getting my transmission rebuilt anyways...

[DrunkenNinja]

I don't use a dealer but my mechanic used to work for BMW so I'm gonna get him to do a full check over on the car...

It's a 2004 Facelift model, I will certainly ask the mechanic to look at the rear transfer case belt and do a software update when there, thanks for the info!!!

I guess it could be the transmission but it seems unlikely as it only does it just before the car comes to a stand still, even if it was down shifting at the last minute or not at all I can’t see how it would have this effect, plus it does not feel like a transmission problem and I can hear and feel all of the down shifts under braking and they appear normal.

If I brake slightly harder everything is normal, It’s just that I am used to breaking more gently than your average driver, also this does not happen all the time, it's actually fairly rare, twice in a journey is a bad day...

I did some reading on the Resetting the Adaptive Driver Memory and I will certainly give this a try, however I also found an interesting 8 page pdf article on the E53 6-speed automatic transmission that quotes the following:



The adaptation to the driver type is made using the values kick-fast, cornering detection, brake evaluation and constant-speed travel.

The driver-type adaptation is restarted each time the vehicle pulls away from a standstill.





If the accelerator pedal is depressed rapidly, the shift program is changed accordingly. This is achieved by the detected accelerator-pedal value being compared with threshold values in the EGS control unit.

The result of this comparison is the proposal of one of the two possible adaptation programs (XE or E in comfort program, S or XS in sport program).

Cornering detection

Cornering detection reacts to the vehicle's lateral acceleration with an indirect adaptation to the driver type. Lateral acceleration is considered an indirect statement of the preferred driving dynamics and does not cause an immediate gearshift reaction (downshifts when cornering could negatively affect driving stability).

The lateral acceleration is calculated by means of signals from the wheel speed sensors on the front and rear axles and from the yaw rate and the road speed.

Brake evaluation

The braking action is evaluated in a similar way to "kick-fast".

The braking deceleration is measured and compared with threshold values in the EGS control unit. The result of this comparison is the proposal of one of the two possible adaptation programs (XE or E in comfort program, S or XS in sport program).



It clearly states that the adaptive drive is restarted every time the car pulls away from a standstill.

Maybe this detection of driver style is only incorporated into newer models, (but I could not find one I could legitamise) as from the guides I read it refers to pressing the Start button which the my E53 does not have...

It seems that by holding the accelerator you are telling the car that you will be driving aggresively during the current journey and the car adapts for the occation...

Personally I think it sounds like a one shot deal, you can manipulate the drive of the car untill you turn off the ignition, after that it resets to its regular adaptive state...

A nice trick that could be used for racers or journeymen but not something long lasting or feasable for the daily commuter...