Siemens MS41.2 EWS, SAP, and rear O2 removal

[Poeman446]

Hello Everyone, First of all, I hope this is the correct place to post this.

I am swapping a S52B32 from a '99 M3 into my '87 325is, and I am looking to modify my Siemens MS41.2 ECU and remove the EWS, SAP and the rear O2 sensors from the software. I am NOT trying to tune spark, fuel, etc. I have downloaded a few of the .bin files (24kb and 256k full reads) and looked at them to see what I could discover. I put them into TunerPro with some xdf definition files that a few guys (who are WAY smarter than I am) over at RomRaider came up with. I've done a lot of research, and the bottom line is that I do not have the background in Computer Science that I need to have to start decompiling assembly language to a readable format and then modify what I need to. For the MS41.2, I have read that to disable the EWS check, modify the 0x08 hex location of the 24k file to "FF". Some other people mentioned also modifying 0x06 to "FF" as well, but it threw a CEL for them. I have not modified my ECU just yet, because I dont want to brick mine, having such inexperience. If I knew what hex locations to modify, and how to do all of this, I wouldn't mind at least trying.

The EWS check is in the 24k file. What about the other things? Also, To get a full read, do I HAVE to desolder (I'm not sure about this process yet... I know it requires an adapter of some sort), or can I use a tool like the BMW Scanner 1.4.0 and a Galletto 1260 cable?

I also want to say that I don't expect anyone to hand me over all the answers, although I would appreciate it if you did... this technology is almost older than I am. I just need a few hints to get me going in the right direction.

At the end of the day, If I can't figure this out, I will just transplant all of the things that I need to to make the ECU happy. I have the antenna ring, key, SAP, EWS, and rear O2s, etc. There are a few people I wouldn't mind paying to reflash my ECU, but I know a few people that I definitely will not pay to reflash it either.

If anyone has anything to offer, please help me out. This technology is getting to be a little old to be kept this secretive.

Thank you all in advance.

[flyfishvt]

You can't transfer any of the EWS items to that e30. It's not wired to accept them. Have someone do an EWS delete and be done with it. If by so e chance you figure out how to accomplish it you would be an angel sent from heaven if you documented the process including how you connected to the dme.

[Poeman446]

Never use the word "Can't". But I understand what you mean, its difficult. Anything can be done though, with enough time and money. I'm staying vigilant. Anything that has been made can be un-made and I'm working on it now with a group of very smart people. I have figured out how to do EWS delete, so that's not a problem anymore. I will document that process as soon as I test it and make sure everything works as it should. If it does, I will share it with everyone here. Other people are also searching how to modify spark advance, fuel, etc. As far as the SAP, thats the main thing I want to get rid of, because I dont want the bulky thing in my engine bay. The rear O2s dont bother me either, I just figured Id get rid of them while I was at it. I think that getting rid of things other than EWS are much more difficult because rather than reprogramming via the OBDII port, you have to desolder the chip and use an eprom burner then resolder it in. All of this is assuming you have decoded raw assembly language and found the SAP, THEN modified it correctly. It gets tough.

[blatant]

You probably already have stumbled across this forum, but check it out if you haven't.
http://m3forum.net/m3forum/forumdisplay.php?f=109

http://m3forum.net/m3forum/showthread.php?t=458115

Very knowledgeable people that will be able to help you if you ask.

[flyfishvt]

Sorry for the word can't. I should know better. A simple solution to the SAP is to use a SAP simulator. People do it all the time. But I see what you're trying to do and anyone who can explain how to do it using software is definitely a friend of mine.

Subscribed.

[Stück]

Why not just convert the engine to OBDI like everyone else does?

[328iJunkie]

^Terrible.

[Poeman446]

I dont want to buy all the sensors, rewire a ton, and I dont want to switch to an inferior system. OBDII tells you so much more on diagnostics and is "smarter". I am also hopefully paving the way to a DIY method to do an S52 swap and keep OBDII. If I figure out how to modify the code, I want to give people the option to reprogram it themselves, although I dont see a lot of people going that route, as it takes time and money. Its cheaper and faster to just send it to be retuned.

328ijunkie, are you also on RomRaider? I really wish I knew as much as you did about the engine management. Half of me doesn't want to ruin everyone's business with the SAP, O2 and EWS deletes, but at the same time, its time... This tech is OLD, people need to be able to reprogram this. It will be some time before I am able to figure all of this out.

[EE05063]

I have a 97 M3 with S52B32 engine and just acquired a T30 laptop and Tiny ADS cable. Would love to figure out how to remove SAP (already physically removed the hardware) , rear O2s and similar. You would think by now this would be commonly available stuff.

[Poeman446]

I have successfully removed the SAP, EWS, and Rear O2 sensors from the ECU. I will be posting .bin files of the 24k file that you need to rewrite. I was using a Galletto 1260 cable and the included software. It worked like a champ. I will be posting a previous post from another forum that I wrote to outline this process. Its not difficult but you have to take your time. I will be updating here soon. This info needs to be released, and it will be. Soon!

- - - Updated - - -

If anyone needs the .bin files for their swap, or just to remove the EWS, SAP and rear O2s (or any one of the three...) send me a PM with your email address and I will email you the file. I knew this could be done, and I thank the kind soul who sent me his .bin files.

In order to write to the Siemens MS41 while it is still in the car, follow the process below.

This relates to the Galletto 1260 cable and software.

1. Attach the Galletto 1260 cable to the OBDII port in the car, and connect the USB to your computer. Turn the car to the ON position. You can then read the ECU data, and read the 24k file from the ECU. NOTE: You MUST have the round cap near the SAP pump ON the diagnostic port. If its not, the OBDII port will not function correctly. The same applies while writing to the ECU, but I'll get to that in step 4 & 5

2. Read the ECU and be sure to save a copy of the file.

3. Open the file that you want to write to the ECU.

4. In order to write to the ECU, pins 14 and 18 MUST be bridged at the diagnostic port to write. This can present a problem because the cap MUST be on the port to write as well.

5. Cut a 2" or so length of insulated wire, skin the ends, and bridge the pins. Curl the wire to the side a bit, and replace the top so that the wire is inside the diagnostic port. You should then be able to write if the cap is on far enough and the wire did not come detached at one end.

6.Write to the ECU using the correct button within the Galletto Program.

7. Success.

I hope this will help at least one person, and I'm pretty sure it will.

I can send three .bin files of various options that can be flashed into the ECU. Be careful, and take your time. I do not take ANY responsibility for damaged ECUs or other electronic hardware/software/firmware.

I am going to try and find the detailed hex locations for all of these features, because I think it would help the community very much.

[flyfishvt]

Just sent a second pm for those files

[Poeman446]

flyfishvt you have an MS41.0 If i recall correctly. This tune will not work on that ECU. Also, I am stopping giving out the tune for now. I am going to test this in a swapped car to make sure everything is as functional as I say it is. I am also going to test the AFRs with a wideband O2 and make sure the SAP and rear O2 delete doesnt cause the car to run lean or rich. Thanks for understanding. To those who I sent the files to at first, be careful, and again I'm not responsible for any damages.

[EE05063]

I can't imagine how SAP removal would cause a rich or lean condition. The SAP only runs for under a minute on a cold start. As far as I know post cat O2 sensors are only used to detect catalyst efficiency. Only the pre cat O2's are utilized by the ECU to adjust air/fuel ratio. This is my understanding of the systems and why I feel it is perfectly safe to remove them. They are all geared towards emissions, not actual drive-ability.

[Poeman446]

And I think that you are right, but I was told something could be different by someone much smarter than me, and instead of melting a $2500 setup, I'm going to test the AFRs for free with a wideband. If it works correctly, I will let everyone know.

I do know one thing, after looking at bin definitions and xdfs for even the 413 ECUs, I am amazed at how much stuff could be changed or rely on other things.

[flyfishvt]

flyfishvt you have an MS41.0 If i recall correctly. This tune will not work on that ECU. Also, I am stopping giving out the tune for now. I am going to test this in a swapped car to make sure everything is as functional as I say it is. I am also going to test the AFRs with a wideband O2 and make sure the SAP and rear O2 delete doesnt cause the car to run lean or rich. Thanks for understanding. To those who I sent the files to at first, be careful, and again I'm not responsible for any damages.

I don't gave a ms41.0 I have a ms41.1

There's no way for EWS delete or sap delete or secondary o2 delete to have any effect on anything. Let me know when you finish testing. I've spent hours searching and I can't find anyone willing to explain ANYTHING about how to get started on this stuff

[rf900rkw]

You can guarantee these random bin files off the internet have ONLY the SAP and/or EWS changed? I have about a half dozen "stock" bin files I've found lurking around the net (likely including the three under discussion). None of them are stock.

- - - Updated - - -

Also, a 41.2 (S52) bin file will not work on a 41.1, as far as I know. Certainly the tuning will be wrong.

[Poeman446]

Correct. Either way, MS41.2 ONLY works on MS41.2. My main concern is that the fuel maps are not stock, ignition timing may be tweaked, etc. I'm doing what I can. Next, there is a 20 page thread on tuning the MS41.1, MS41.2 and general MS41 stuff. Google it. The files are there, but I can promise you that if you flash MS41.2 software to a MS41.1, You are going to screw it up, and be out of an ECU. Your next option is to get a Galletto or similar cable, read your 24k partial file, and then change it around yourself to make the changes. As far as EWS, I know it is in hex location 0x08 for the MS41.2. Is it the same in MS41.1? I don't know, it's your gamble, and I am trying to figure that out in my ever decreasing free time. If you get that far, 0x08 needs to be changed to something higher than it is. The files that I have suggests "96" and some people suggest "FF", although I have heard that "FF" is unnecessarily high, and can cause a CEL for muffler flap issues. Remember though, that any changes to the software will require a checksum correction or you will get a CEL for a bad ECU.

As far as the files that I have, I can't guarantee anything. I don't know enough about it to tell you its fine, or if its going to decrease the life of your engine, or make it more powerful. I don't know. I do have my original stock tune, and I can compare it to the newer files to see the adaptations, and the maps. This takes time, but I will do it asap to suggest that the fuel, spark, etc has not been changed.

You're right about no one talking about how to get started on this stuff. Unfortunately a few people make a lot of money by knowing how to do these things. Its their right to make this money, because after trying to disassemble hex code and make sense out of it (some people doing this for a year or so to try and understand it...) it takes a lot of time. I'm just getting started now, and its overwhelming. I'm trying to release all of the info that I can, and I will, unless it is someone's proprietary tune, or anything that I have been given and the owner doesn't want it released.

Again with the deletes. They might not have any effect on anything, but then again, they might. Someone ten thousand times more experienced than me told me that it could have an effect. Still, unverified, however I have no reason to distrust that person, and in fact, he has been one of the few people to steer me in the right direction.

Thanks.

[rf900rkw]

Your three bins have the Rev limiter set to 7040, and the speed limiter disabled. Obviously some tune of some sort. Until I find a stock 41.2 bin, I can't say what has been changed in the fuel and timing maps.

[Poeman446]

PMed. I compared the bins from when I sent it off until i got it back with the deletes. I see several changes. The ews, and one location at 0x22C, which is the Rear O2s (changed to 00, from 02) as well as two tables that are supposedly the SAP tables. I am going to post a quote from the other forum. The guy heading this project figured the following information out.

"
EWS disable byte of x08h is confirmed as we thought a few pages ago. Though, the value for EWS delete goes from 16h to 96h instead of to a confirmed working FFh. Maybe it doesn't matter?

SAP delete has two tables 8 cells long. Axis location references at x32D4h (B0 2D) and x32F8h (C2 2D).
Axis is 8 bit. x2DB0h and x2DC2h. Both are "30 33 40 47 53 57 79 7C"
Data is 16 bit. x32D6h and x32FAh. "19 00 9C 04 9C 04 9C 04 9C 04 9C 04 9C 04 01 00" and "19 00 9C 04 9C 04 9C 04 9C 04 9C 04 9C 04 00 00" respectively.
It seems this "SAP delete method" zeroes out the data bytes to 00h.

Rear O2 delete is controlled by 1 byte at x22Ch. Setting the existing 02h to 00h seems to delete the rear O2."

Apparently the first bin that I had was modified to be tuned, and also had the revlimiter changed, and speed limit deleted.

[EE05063]

Your three bins have the Rev limiter set to 7040, and the speed limiter disabled. Obviously some tune of some sort. Until I find a stock 41.2 bin, I can't say what has been changed in the fuel and timing maps.

Can one not simply extract the stock bin file using the Gilletto cable and software? I have one on the way, also have an ADS cable and bmw software. Could it be as simple as me extracting my stock file to examine? If so I'll get it when the cable comes in.

[rf900rkw]

Yes, it would be that simple. My original DME has some tune applied by the previous owner.... and it is sitting in a drawer. Once I get my off-vehicle rig built up, I'll be able to dump it and a 41.1 I have here. But neither are a virgin example, obviously.

[EE05063]

Well I will get that for us as soon as I get the stuff. I assume it is a 41.2 as it is a 97 model S52. Never been modified.

[Poeman446]

The Galletto cable is very simple to use. I got mine from Amazon for $15 or so. The software is somewhat vague for the MS41.2, but just use the MS41 subsection and use the 2.8i to read (it thinks its a 328i... it works fine though.) When I tried to read the data using the 3.2i under MS42 it didnt work. Anyway, yes the Galletto seems to be the go to cable to read and write. In order to write, you need to bridge pins on the diagnostic port though. It's not difficult.

ALL S52s run the MS41.2 (unless they have been modified to OBDI).

[EE05063]

Mine will get here one day in middle of February it says. Got it on Amazon, apparently it is being fashioned from mythical materials and taking the same route the Nina, Pinta and Santa Maria did to get here.... lol

[Poeman446]

That's weird. I got mine in two days via amazon prime, but the seller was rather bad. My CD came cracked in half and amazon refunded my money. The software is still online so it worked out alright. Good luck getting it soon.