Modifying Motronic 2.3.2 ECU hardware and software.

[vwnut8392]

Time to call you on your bull*hit.
No amount of factory docs, even if it was available would help you add proper datalogging to the ECU, add launch/nls to the ecu, or run the ecu without a MAF on custom code.

Everything I really know, I know through disassembly. Something you will never be able to do.

i dont want datalogging, i already have a solution for launch control/NLS and im content with a MAF on the car. the car in my stable that needs all these features is setup for VEMS which does all of this and more. nice try at call my BS. i said it above and i'll say it again, im not trying to achieve anything that involves custom code. the ECU in it stock configuration works just fine the way it is for me. i would love to meet you in person and have you treat me like you do on here. your pretty mouthy with the atlantic ocean in between us.

[prj]

another thing that puzzles me is that the people who have all of the knowledge of this ECU always claim to have or have access to this mythical factory documentation.

Time to call you on your bull*hit.
No amount of factory docs, even if it was available would help you add proper datalogging to the ECU, add launch/nls to the ecu, or run the ecu without a MAF on custom code.

Everything I really know, I know through disassembly. Something you will never be able to do.

[vwnut8392]

I have a lot of empathy for what you are trying to achieve on this, but wouldn't it have been much more effective in terms of time and cost to buy an aftermarket ECU than destroy three engines ?

I cannot foresee anyone who has invested the hard yards, months and years of effort in unpicking the factory Motronic secrets is going to publish an XDF for someone like you - I don't mean that to sound disrespectful of you (or anyone) personally. But, unless an experienced tuner goes into retirement or decides he has no interest in 20VT anymore then why should publish something which potentially reduces their income ?

The way that I learnt what I did was a mixture of reading good Bosch reference materials, and sharing findings with others who have electrical or software expertise to move things forward.

The only way an 'open source' group to publish the internal workings of the 20VT Motronic is if a collection of guys with really strong programming capability (especially in 8051 disassembly) can collaborate in a way where none of them can make financial gains from exercising their scarce skills.

The people with skill at unpicking these things are very rare and kind of 'rain man' state of mind is required to see patterns in the code etc so the chances of finding a forum of like minded 'not for profit' people is extremely low.

I started the ESIM project on this forum as an open way to share how a 20VT ECU can be run on a bench... connected to a tracing emulator etc while engine speed, load, throttle position etc are adjusted electrically to help myself and others see how the various tables and constants are accessed in the OE software. This gives a very safe way to verify things like injector constants, dwell constants, rpm / speed limiters as well as exploring the main tuning tables.

I have only recently made some decent progress on that, but it can help folk like yourself with a natural interest to learn more about what is happening inside the ECU, but as you say you have no programming expertise then I really don't fancy your chances of making much progress - again no offence intended by that - its just the scale of the problem and the tools, education & experience required to solve it is considerable.

Also - even if you did manage to unpick the secrets of the motor chip... there is a whole other world of pain to understand how it communicates with turbo chip... and another wall of code to wade thru understanding how that chip adjusts for ambient pressure and knock. I have an appreciation of what is in there, but only a handful of guys globally (outside of Bosch) have any real insight how all that works.

Seriously - have a look at ESIM and see where that can take you - either with factory ECU, but I bet you will make much faster progress with it on VEMS... that way you can ignore how it works and where the important tables are... you just need to know where the tables & constants are with VEMS documentation on how to use them... and you will find some baseline tunes for 20VT to get you started as well - waaaaay simpler.

I understand and respect your point of view. my problem is im not easily discouraged. even with no programming experience i will keep working at it till i figure out what i want to know. like i said before i have no interest in how the ECU works directly, all i simply want to do is be able to adjust the basic mapping accordingly to raise boost, fuel, timing, rev limiter, and add larger injectors if needed. im not looking to write custom code to improve the ECU in any way as i feel the ECU works just fine the way it is with basic mapping mods. i've even had ideas of migrating the AAN away from motronic 2.3 because of the lack of information to do anything with it. i had my sites set on using motronic 4.4 from a turbo 5 cylinder volvo as its the most similar engine hardware wise i can find plus the tuning for it is completely open source.

when you say it takes a person thats in a special state of mind i totally agree. since i have no programming background i have asked my cousin for help as he is a fairly extensive programming background and his mind is blown away by how this ECU works. another thing that puzzles me is that the people who have all of the knowledge of this ECU always claim to have or have access to this mythical factory documentation. well if the knowledgeable ones have access to it thats why they know what they know obviously. if i could track down this unicorn of a document i would be willing to pay the price for it and the first thing i would do with it is post it up right here for free regardless of what it cost me.

i have seen your work on building an engine simulator as well and i do admire you for attempting this task. have you ever heard of the jimstim engine simulator that the megasquirt guys use? i have one that i was using with my VEMS ECU to do the basic trigger wheel setup before i installed it in my car. i had the same idea but to use 2 jimstim engine sims to achieve the same result. i havnt followed up on messing with this idea yet because i dont have a second jimstim yet or the hardware to program it with new trigger wheels. The jimstim's are pretty cheap in price though and can be a pretty useful tool when it comes to experimenting with most any ECU. i have attempted to hook it to a stock motronic and monitor values in vag com like TPS, coolant temp, air temp etc and it does look like its going to work. my plan was to setup emulate the single firing pin on the flywheel and the cam sensor with one jimstim to keep them 2 in sync and use a second jimstim to get the 135 teeth on the starter ring. with 2 jimstims over all i feel most of the hardware on the AAN engine. now its just an idea so please dont flame me for it.

I do own a VEMS ECU too and i will say that im not very pleased with that investment at all. bought it second hand but was still brand new and never installed on a car. the ECU lasted 11 hours on a car and failed. i was told the processor failed by VEMS and they claim they cannot explain what caused the failure. it obviously failed for a reason and i would like to know if it was my fault or theirs before i go paying them to have it fixed. so the whole VEMS craze has put a sour taste in my mouth as well.

i run the VEMS ECU on my AAN swapped 4000 quattro and a stock but modified ECU in my S6 avant. i would have stayed on an OEM ECU in my 4000 but i was at the point where i needed a higher rev limiter because i installed HD valve springs, 7A cams and bigger injectors. at that point the stock ECU couldnt be adjusted for this so i tossed it on the shelf and bought the VEMS ECU. well the 4000's stock ECU is now in my avant and it works just fine for what modifications i have done, it is a daily driver so im not trying to get out of control. so yes i did play in the VEMS ring for 11 hours prior to faliure and through this all i have gained is a very expensive door stop and an even more expensive lawn ornament.

[S2central.net]

i personally have ruined 3 AAN engines among all the equipment i've bought and im not crying about it, its the price i paid to play.

I have a lot of empathy for what you are trying to achieve on this, but wouldn't it have been much more effective in terms of time and cost to buy an aftermarket ECU than destroy three engines ?

I cannot foresee anyone who has invested the hard yards, months and years of effort in unpicking the factory Motronic secrets is going to publish an XDF for someone like you - I don't mean that to sound disrespectful of you (or anyone) personally. But, unless an experienced tuner goes into retirement or decides he has no interest in 20VT anymore then why should publish something which potentially reduces their income ?

The way that I learnt what I did was a mixture of reading good Bosch reference materials, and sharing findings with others who have electrical or software expertise to move things forward.

The only way an 'open source' group to publish the internal workings of the 20VT Motronic is if a collection of guys with really strong programming capability (especially in 8051 disassembly) can collaborate in a way where none of them can make financial gains from exercising their scarce skills.

The people with skill at unpicking these things are very rare and kind of 'rain man' state of mind is required to see patterns in the code etc so the chances of finding a forum of like minded 'not for profit' people is extremely low.

I started the ESIM project on this forum as an open way to share how a 20VT ECU can be run on a bench... connected to a tracing emulator etc while engine speed, load, throttle position etc are adjusted electrically to help myself and others see how the various tables and constants are accessed in the OE software. This gives a very safe way to verify things like injector constants, dwell constants, rpm / speed limiters as well as exploring the main tuning tables.

I have only recently made some decent progress on that, but it can help folk like yourself with a natural interest to learn more about what is happening inside the ECU, but as you say you have no programming expertise then I really don't fancy your chances of making much progress - again no offence intended by that - its just the scale of the problem and the tools, education & experience required to solve it is considerable.

Also - even if you did manage to unpick the secrets of the motor chip... there is a whole other world of pain to understand how it communicates with turbo chip... and another wall of code to wade thru understanding how that chip adjusts for ambient pressure and knock. I have an appreciation of what is in there, but only a handful of guys globally (outside of Bosch) have any real insight how all that works.

Seriously - have a look at ESIM and see where that can take you - either with factory ECU, but I bet you will make much faster progress with it on VEMS... that way you can ignore how it works and where the important tables are... you just need to know where the tables & constants are with VEMS documentation on how to use them... and you will find some baseline tunes for 20VT to get you started as well - waaaaay simpler.

[-ice-]

It took years for you to find out how to set the rev limiter. Do you really think people want to share information with you they have worked for a long time?
Without this thread and the "selfish" hints you wouldn't be able to do this now.

Please give me your money you have worked for the last years. I think everybody has the right to spend your money freely

It's not a personal thing with you, Nobody will get any information if he asks like the way you do. The internals of a comercial ecu are not published on wikipedia.

If you want an open ecu, then buy a Vems. But please don't blame the people if they don't want to tell you everything.
I will never release an xdf, because there will be people how sell it or produce damage to their cars or even humans, because they don't know what the are doing.

You should not play with your ecu if you absolutely don't know what you are doing.

Working on your own is the only way you can get further in this case...

Regards

[vwnut8392]

he just started to work on his own, very good

Ive been working on this for a very long time. the only difference between me and everyone else is i'll post all of my information in detail so no one else has to go through the bull crap i did. no body deserves to be treated like i have been by the audi community while trying to figure any of this out. Im not going to give "hints", im going to explain what i've done and how i did it great detail so people actually learn instead of getting frustrated and giving up. i myself am not a programmer nor do i have a programming background. all i want to do is be able to perform basic ECU tuning on my car. i could care less how the internal ECU code works. one of my close friends is considered one of the best honda tuners in the land and he doesnt understand a single part of how the ECU code works, he just knows how the engine works and how its supposed to act when engine modifications are performed. whats so hard about one of us releasing an XDF for tunerpro that has all the basic info plugged in so that one can blow up their car at will. the only reason i keep pursuing this isnt to make money tuning cars or for any sort of fame, i keep on going because i think the people that want to tune their cars themselves should be able to. if your in this to get rich than your in for the wrong reason. it baffles me how this car community has gone from people helping each other and sharing information freely to everyone being selfish with information and basically telling everyone to piss off and go figure it out for yourself. The BMW and volvo ECU community is a great example of how if information is shared freely in great detail how fast it can grow and evolve. go ahead and cry about all the money you've spent doing this because your not the only one obviously. i personally have ruined 3 AAN engines among all the equipment i've bought and im not crying about it, its the price i paid to play. with venting my frustations aside im going to drag myself back into the depths of the internet with my trusty calculator and keep crunching numbers till i have more solutions or should i say secrets cracked to the motronic 2.3.2 ECU. rant over.

Oh and on the XDF note here is the 551AA definition timing/fuel definition i've been working on. it has the rev limiter in there plus the rev limit fault code scalars. also i have what i think is the injector scalar or KRKTE too, im not a 100% sure on the math for KRKTE yet and thats why i havnt posted any info on figuring out what math is behind it. this definition will correct the checksum as well. if there is any false or info you feel is missing please do all of us a favor by sharing the info and correcting the problem.

[-ice-]

he just started to work on his own, very good

[vwnut8392]

so as i posted previously about the rev limiter in the 551AA and 551B files the conversion factor is 100% correct. as for the expression for tuner pro the one i posted above doesnt work when it comes to adjusting the limiter as -ice- had said in a previous post.

Rev limiter for 551AA and 551B is at hex offset 0x8373 and is a 16 bit value.

Here is the proper expression for tuner pro so the the limiter shows up properly and scales proper as well. Also set the size to 8 bit on the general tab.

7499440/(X*pow(2;3))

also so you dont get the fault code for over revving the engine you want to create a second scalar just like your rev limiter scalar. The hex offset for that follows right after the rev limiter at 0x8375. this is a 16 bit value as well but remember when you set your scalar up it has to be an 8 bit value.
You use this expression for the rev limiter fault code.

7499440/(X*pow(2;2))

i realize that the 551C and up files have a different way of calculating the rev limiter than the 551AA and 551B files as well. im going to continue to work figuring out that rev limiter as well. lastly i've been working on the injector constant too and i will be posting all of the data for that once i confirm its right.

[vwnut8392]

well i've been using the 551C and 551D files and i think i've come to realize that the 551C and up calculates the rev limiter differently than the 551AA and 551B files. This is what i did with the 551AA and the 551B files and it works out perfectly.

551AA 0x8373
CF/(82*2^03)=7211
CF/(130*2^3)=7211
CF/(130*8)=7211
CF/(1040)=7211
conversion factor=7499440

i than used the conversion factor on the 551B file at the same hex offset and got a rev limiter of 6602RPM.
i got 6602 from the conversion equation -ice- posted in an eariler post using tuner pro.

This is exactly what i have in my conversion expression in tuner pro.

7499440/((X>>8)*pow(2;(X&0xff)))

and if this is the rev limiter than following directly after it would be the RPM limit of 7440 that sets the fault code for engine RPM exceeded at hex address 0X8375. i tested this using the conversion factor above.

[Acki]

I don't know. I use a fix offset, no big equation. Verified in 2 minutes in vehicle.

[vwnut8392]

This is exactly what im doing. i plug this into tunerpro and it i get 692 RPM. Im working with the AAN.

Conversion factor/(X*2^Y)=rev limiter

CF/(5B*2^06)=7211
CF/(91*2^6)=7211
CF/(91*64)=7211
CF/(5824)=7211
41996864/(5824)=7211

So i plug it into tuner pro just like this
41996864/(X*2^Y)
The end result is 692 RPM. i feel there is something missing from this equation.

[Acki]

What is the problem?
Serious? Change the value and look what engine speed is limited. Then you can correct the factor?!

[vwnut8392]

You have posted the same question some pages ago and we have already discussed it!


If you can't find it on your own, search on the internet for the revlimiter (assembler) code. You will find some forums, where it is posted. You will also find it then in your code.

Regards

i know where the rev limiter is along with the fault code about engine speed exceeded, i just cant figure out the math to make it into a real world value.

[-ice-]

You have posted the same question some pages ago and we have already discussed it!


If you can't find it on your own, search on the internet for the revlimiter (assembler) code. You will find some forums, where it is posted. You will also find it then in your code.

Regards

[S2central.net]

That site is incorrect for the 20VT method !