Sneaky Ecu Reset Boosts Performance

[hawk20]

In another thread a member posts that he drove a second-hand ML55 and found it slow. http://forums.mercedesclub.org.uk/showthread.php?t=33815&goto=newpost

The trouble may have been that the gearbox adjusts to the way the car has been driven. If it has been driven slowly by previous owners the gearshift pattern will adjust to suit that style. It may equally have been in much heavy traffic.

It is possible to get the ECU to unlearn the slow behaviour according to US websites. Here’s one example: -
http://forum.mbworld.org/forums/showthread.php?t=148019&highlight=works

Here’s the first posting: -
“Figured what the hell, and gave it a shot per the instructions someone posted. I get her out and punch it from a start and it feels weird....a bit unstable. I am like great, I broke something, then I realize it is pulling like a friggin freight train and my a$$ is wiggling. I can't wait til the ECU sets me up this way....maybe better, that would smoke.

Anyway proceeded to do some launches and I can really tell a difference in shifts. Someone said it best....feels like the car had a tune up or something.

I COMMAND all of you to try this (well if you are not happy with your current setup). I just know now my car set me up wimpy due to long highway miles after driving back from Klee. Enjoy!!!

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 ECU to reset.”

Could be worth a try?

 

[speedybiker]

Actually it's nothing new.
The car learns your driving from the way you drive and learns from it.

What you have explained just resets it.

Regards,

Alex.

 

[Dec]

Yes that works on mine, I think that was covered here before but well done for brining it up again Hawk as it will be useful for those who don't know about it.

Dec

 

[evdok]

Your answer

http://www.cksperformance.com/Mercedes/Mercedes.asp?SID=27

 

[recycled]

thanks but nothing new there. that is the procedure for ressetting the ECU especially after a MAF or battery change

 

[hawk20]

Yes that works on mine, I think that was covered here before but well done for brining it up again Hawk as it will be useful for those who don't know about it.

Dec

Sure. I don't think anyone is claiming it is new. Merely that it is useful especially after long periods in heavy traffic or when there is a desire to give performance a boost.

What I find interesting from following the US thread is one is still left with a 'does it or doesn't it really work' feeling. And what is not clear is how quickly our gearboxes adapt if we start driving more briskly. Presumably you get the same effect but just with a bit of a time lag. problem is of course on the UK's congested roads, the normal pattern for many is to be held in long lanes of traffic.

 

[television]

You only have to use kick down a couple of times to liven things up, thats fine going down a open road, when you hit a 30 or 40 zone you stop kicking down and the car reverts back to a leisurely drive.

Further to this try the kick down when getting onto a motorway then use cruise, and it will use the kick down to maintain the set speed.

Drive onto the motorway in a leisurely manner, and set cruise, it will take you gently up to the set speed.

 

[BTB 500]

Yup this was posted here more than two years ago:

Resetting auto gearbox memory without disconnecting battery..


Lots of more recent threads on it too e.g.

The Autobox Reset Theroy
C43 Adaptive Transmission Reset Procedure?
can you reset the gearbox?
Resetting transmission memory C43

etc.

 

[crockers]

Is this the same for ALL MB auto boxes? Even the new 7-tronic ones?

 

[television]

Is this the same for ALL MB auto boxes? Even the new 7-tronic ones?

Yes all makes of cars including non MB with ECU's for the gearbox.

 

[DansSlk]

This wont work on 7G boxes.

It wont learn in P / N

 

[hawk20]

Yes all makes of cars including non MB with ECU's for the gearbox.

Certainly being claimed to work on the 7 speed boxes in the US and if they are adaptive, it's hard to see why resetting should not work?

 

[DansSlk]

Certainly being claimed to work on the 7 speed boxes in the US and if they are adaptive, it's hard to see why resetting should not work?

I find that unlikely, i think BlackC55 (name escapes me at the moment sorry) did a test on Star and found that the adaption's where not altered in any way by this, I've also done the test with Star and had the same results i.e No change.

I also know that the 7G has its learning function's inhibited in P, N and R it will only learn in D in C/S mode's again its inhibited in M.

In reality this is not a reset but a trick being played on the transmission controller i.e It sees full throttle and reacts to that even if the engine is not running.

The new boxes are smarter and they can't be fooled like this.

 

[television]

I find that unlikely, i think BlackC55 (name escapes me at the moment sorry) did a test on Star and found that the adaption's where not altered in any way by this, I've also done the test with Star and had the same results i.e No change.

I also know that the 7G has its learning function's inhibited in P, N and R it will only learn in D in C/S mode's again its inhibited in M.

In reality this is not a reset but a trick being played on the transmission controller i.e It sees full throttle and reacts to that even if the engine is not running.

The new boxes are smarter and they can't be fooled like this.

This was also shown to be true on the USA forums, No change when first posted some 2 years back.

Am I correct in saying the the gearbox ECU has some memory, but limited and some faults need reading off before turning off the engine otherwise they cant be read out

 

[DansSlk]

Yes it's limited in memory and speed when compared to some of the other control units in the car especially the engine controller but then it has a simpler job to perform.

I think that minor codes are that are set as stored are erased either at shutdown or after a few shutdowns to give you a chance to connect to a Star and all are gone when power is removed (in contrast to the ME that can store codes for ages), the major ones stay so long as it has battery/umbilical power.

 

[BTB 500]

Yup I had an occasional gearbox problem on my R129, and the faults were still there when I eventually took it in to have the codes read.

 

[hawk20]

So could somebody technical summarise when they think the reset does work and when it doesn't -or on which boxes it works and on which boxes it doesn't. And is there any difference diesel or petrol?

It may be an old topic for some but on the US threads many say it works and quite a few say it doesn't. Confusing.

My interest in all this was aroused by the guy driving an ML55 and finding it 'slow'. It had been used for towing a caravan etc and I merely wondered if the adaptive box had got used to slow towing etc etc.

 

[television]

So could somebody technical summarise when they think the reset does work and when it doesn't -or on which boxes it works and on which boxes it doesn't. And is there any difference diesel or petrol?

It may be an old topic for some but on the US threads many say it works and quite a few say it doesn't. Confusing.

My interest in all this was aroused by the guy driving an ML55 and finding it 'slow'. It had been used for towing a caravan etc and I merely wondered if the adaptive box had got used to slow towing etc etc.

You will have to accept that it does nothing, I have always said this, and so do all of the techies

You see there is nothing in the car that can do it

 

[hawk20]

You will have to accept that it does nothing, I have always said this, and so do all of the techies

You see there is nothing in the car that can do it

Are you saying it does nothing on any of the boxes -not just the 7 speed?Several postings and links on page 1 of this thread appear to be saying it does work. I do not claim to know, but I am interested to know the truth.

 

[television]

Are you saying it does nothing on any of the boxes -not just the 7 speed?Several postings and links on page 1 of this thread appear to be saying it does work. I do not claim to know, but I am interested to know the truth.

My answer was for the 722.6 boxes and stands as far as I am concerned that stands.

I studied the ECU almost 2 years back and there is nothing there that can do it