kevink2

This would be most effective for atx models. Our 08 had learned some bad habbits and became sluggish, so this time I went to the "secrets thread" for a concept I had:

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10) Steps to Reset the TCU. Resetting the TCU will reset transmission to factory shift points and the car will 'relearn' your driving style.

(1.) Turn the ignition key to the on (not start) position.
(2.) Press the gas pedal to the floor and hold for five seconds.
(3.) Turn the key to the "off" position (don't remove the key), then release the gas pedal.
(4.) Wait at least two minutes for TCU to reset. (key in)

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I think this really just sets the range of the TB, so you get max signal voltage ( ~4.6V ) when pedal is floored, and is not mostly related to the TCU.

On our 08 atx, there is a false stop at about 80% pedal travel, and much more force is required to press the pedal further to the floor.

THE "MINI SPRINT BOOSTER" MOD:

I did the item 4 steps in secret #10 to reset the TB, but only pressed the pedal to the hard spot, instead of to the floor. And be sure to leave the key in during step (4) .

The results were great. Due to this method, at about 1" typical pedal stroke, you are telling the ecu and TCM that there is about 20% more load than before the mod. The benefits include:

-> higher shift points
-> quicker/easier to downshift
-> a more peppy drive with less lag
-> cost is $0

As far as 0-60 or 1/4 mile times, no improvement there.

I hope others with atx models try the same mod, to get more driver impressions.

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denot

Man, can you help what do you mean by "on" position? how many click you've turned after inserting the key?

Also, how did you know it has reset? any sign?

thanks

kevink2

on pos'n is just one less click than the crank position. I think it's just 1 click, but verify it by just starting the car.

no confirmation, other than very spunky response. hard copy this:

my mod'd TCU reset:

(1.) Turn the ignition key to the on (not start) position.
(2.) Press the gas pedal to "stiff position" and hold for five seconds.
(3.) Turn the key to the "off" position (don't remove the key), then release the gas pedal.
(4.) Wait at least two minutes for TCU to reset. (key in)


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jaimejrivera

Did it this morning before leaving home and it works like a charm!!!

clkcadet

How do you reverse this mod? Also I guess it decreases mpg?

jaimejrivera

Reset with the fully depress pedal.

-Reno-

should i press the kick-down button when i flooring the pedal too?

also, do i get notification that it has been reset?

mac911

I believe the point of this thread was normally in the procedure you do go all the way through kick down button for a normal reset.

However, the poster had the clever idea of holding the pedal only to the resistance point (not engaging the kick down button).

No, you do not get a notification, although sometimes after the 2 minutes specified, you can hear the computing rumbling a bit, restarting.

kevink2

yup.

also, I recall reading in the owner's manual? that there is no longer any actual switch at the kickdown point, but MB retained the resistance point for some reason.

mac911

It's such a significant click too, when you you go past the resistance point. The car does seem to move more after that point.

My SLK does not seem to have the definitive point like that, which you can physically feel. It's just smooth to the floor.

Savage c-300

Thanks for the tip, I'll have to try this when I get in my car today.

aowhaus

I did this yesterday.
It was a nice improvement, nothing drastic, but still nice.

Draz

How is it done on a keyless car?

delirium

does the computer slowly go back to being sluggish if the car is driven normally?

white46

you can take the cap out and stick the key in.

Cpbball3

I did the normal ECU reset and it worked like a charm. I pressed the pedal down all the way to the floor. I literally pulled out of the driveway and floored it down the road and it drove like a different car - I was amazed.

I am interested to try this mod and see if it works better/same/worse. I will let everyone know!

mac911

Yes in my opinion.

I'm actually mad I reset it the other day.

The reason being is that over time I had done a lot of spirited driving and got the transmission behaving better.

Now, after the rest I've been more around town peaceful driving, so I think the transmission is slipping back to how I don't want it.

FrankW

doesn't matter how far you press the pedal down. the TCU reset it's value to zero. it will re-learn your driving pattern in couple days.

the new pedal's kick-down button as said it doesn't work. It's only a spring loaded button. you can take it out if you want. it's just there to remind people that fully pressing the throttle will force down-shift.

kevink2

My experience is you will not always get a downshift if you go beyond the resistance point .... only if other parameters demand it. This is also mentioned in the owner's manual.

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Thanks for the people that tried this mod .... seems like most people liked it.

jon3sh

Wow works like a charm.. Thanks Wondering if this trick will apply to Bimmer 328i 2009 model my dad's car lagging on first gear.

PolarWhite2014

I did the reset last night and did about 20 mins. of spirited driving. So it's going to take a few days then. Say 50 miles or so of driving? So this weekend I need to drive it like I stole it ? Ok will do. Thanks for the great advice.


Really tho it does feel better and will likely do this reset every few weeks or so. I come from 2 previous 335i's so my foot is in the pedal most of the time as I'm used to that extra hp and kinda have to lean in to it with this car to get close to the acceleration I used to get.