How to tune your motronic!

[KOOTER]

We will lay out some motronictuning info here and I will answer question related to your BMW,Porschw,VW,Audi,and most other european cars.All we need is to get Kris to host some chip files to work with and we can get started.

[Digital K]

i\'d be more than happy to
B)

[OptimusGlen]

sweet!

[KOOTER]

A little background info on the Chuck B chip tuning project.

I started out with a chip burner/reader and a few tuned chips and a stock chip.It sounded pretty easy at the time,find th differences and tune them for what I wanted.Boy was I wrong.

I thought I had the world dicked at this point because the maps stuck out like a sore thumb.The next question was the lead in for more than I had ever bargained for.

I will try to add to this daily and get all the info out on how I went about solving the motronic puzzle.

[Digital K]

B) cool

[KOOTER]

Lets start out with the 93-95 OBD1golf/jetta chip file.Everybody get it downloaded and we will start here.

http://www.bifpowell.com/motronic/TP,obd12l,stock.dat

Now open up your hex editor(winhex) and open up the file.The first thing we need to do is find the checksum and be able to recalculate it.

The checksum in most motronic chip files is by the file ID tag.This is usually located after most of the code and the maps in the file(we will get to that later).In this case its at CF00 and CF01.The checksum is a 16bit checksum and is the total of the block from 0000-CEFF.If you click edit- define block and type in the 0 for the start of the block and CEFF for the end of the block the hex editor will highlight that part of the chip file.Now you have the block selected to checksum.Click tools-calculate hash.On the drop down pick 16bit and then OK.That will spit out the checksum of the block.You will also notice this matches the locations CF00 and CF01.

This is the most basic type of checksum and it will be used in all types of chip files along with a whole bunch of other CRC and CRC32 and alot of other types when we get to the ME7 stuff.For mow we are just going to learn this part.On a side note for the AEB cars there is only one more step.

[KOOTER]

There are also other ways to get around the simple types of checksums(ME2-ME5).There is a cheat method where you can checksum the whole file of the stock file and then find a blank spot around the maps to add/subtract from the file to make the total checksum add up to the same as stock.

This works well if you tune with an emulator because the ecu only checks the checksum on startup.I recently had to do this on a OBD1 BMW that I tuned.

[KOOTER]

We can thank mr biff for hosting he files for us.

[Digital K]

too bad I dont have motronic, I love to dick w/ stuff!

[KOOTER]

A $50 chip burner and you would totally be in heaven.

[KOOTER]

Now if you open up the chip file in the hex editor and go to A700-A873.These are the map pointers.They point to every map in the chip file.Lets look at the first two #s.

AB and 00.Thats your address of the first map on the chip file AB00.Next map is AB26.Pretty simple huh?This is all stuff I had to figure out on my own by hours of messing with chip files in visual programs and hex editors.

[KOOTER]

Lets start off with the things that you will need to do this.(free downloads)

http://www.evc.de/ftp/winols/WinOLS_DEMO.EXE
http://www.x-ways.net/winhex.zip
http://tunerpro.markmansur.com/download/SetupTunerProFree_v414.exe