What Cpu In Motronic 1.3?

[zilog 0]

I am in addition to changing the fuel/ignition maps in my XU9JAZ-powered car trying to understad the code all in all. I have taken a .bin of the EPROM, but before I can do anything more useful than randomly poking in it, I need information on what the bosch-remarked chips inside really are. I have read that the old motronic used CDP1802, but my unit doesnt resemble the pictures those guides have.

 

Any information on this unit is appreciated, with a bit of luck I will be able to understand the code well enough to figure out the CRC check, map indices, and maybe even add some anti-theft mechanism to it (maybe need to pulse the throttle in a certain manner at start-up to make it start?)

 

EDIT: my unit is marked "BOSCH 0 261 200 162" if that is of any help

Edited October 31, 2007 by zilog

[zilog 0]

I found this http://www.e34.de/tips_tricks/motronic/m1_3.pdf, and it seems to be correct in its statement about a 80C515 CPU.

[zilog 0]

Anyone know the address of the CRC byte, and over which range it is calculated?

[TT205 42]

Maybe a moderator can move this post to Aftermarket Engine Management Systems - then you will hopefully get a useful reply

[Dandu 0]

Hi zilog,

 

as far as I know, your ECU is only capable of checking the whole data. I don't know where the appriopriate checksum is stored, but it's actually no problem to change important values and readjust unimportant values to get the same checksum as before. At the end of the file are enough values the change (with no effect).

 

If you need further assistance: location of ignition and injection maps, rev limiter ... feel free to ask.

 

Bye Dandu

[zilog 0]

Hi zilog,

 

as far as I know, your ECU is only capable of checking the whole data. I don't know where the appriopriate checksum is stored, but it's actually no problem to change important values and readjust unimportant values to get the same checksum as before. At the end of the file are enough values the change (with no effect).

 

If you need further assistance: location of ignition and injection maps, rev limiter ... feel free to ask.

 

Bye Dandu

 

Thanks for the input.

 

I have found the maps to start in the following locations:

AFR idle: 0x662E

AFR partial: 0x6662

AFR full: 0x6640

 

ign idle: 679A

ign partial: 0x67FE

ign full: 0x67CC

 

I would really love to get an explanation to how all the values are used, how I can change the rev-span for the different columns, air flow sensor-readings for the rows etc. I understand this far, that the values in the fuel maps correspond to (value/128 +1)*lambda_1 or something along that line - but I would like more information on how the exact fuel amount is calculated. After all, I am doing this to map in a camshaft with relatively much overlap - and therefore I probably cant trust lambda readings for low rev counts.

 

I would also like to know how the ignition timing is calculated, and what I probably can change compared to stock since I have a cam with more duration and overlap.

 

/Daniel

[Bam 0]

hi mate,

 

here are some formulas...try this:

 

Bosch-Motronic f(n) = (n-30)x 0,75

some Bosch f(n) = (n-509x 0,75

 

Bosch KE-Motronic und Mono-Motronic

f(n) = [(255-n)/6] +1

 

Digifant +1º vorverstel. = -5 nummern

 

Siemens 1:1

 

IAW f(n) = n/4

IAW 8P f(n) = n/2

 

GM-Siemens 5 nummern dazu sind 1º mehr Vorverstellung

 

GM-Delco f(n) = n/4

 

i've also attached some thing....

 

have fun.

 

cheers,

miklós

Steuerger_te___Chips.zip

[Dandu 0]

Hey zilog,

 

regarding my documents the ignition and injection maps are located somewhere else. Do you get in trouble sending me your file? After that I can give you the proper informations for sure.

 

Bye Dandu

[zilog 0]

Hi zilog,

 

as far as I know, your ECU is only capable of checking the whole data. I don't know where the appriopriate checksum is stored, but it's actually no problem to change important values and readjust unimportant values to get the same checksum as before. At the end of the file are enough values the change (with no effect).

 

If you need further assistance: location of ignition and injection maps, rev limiter ... feel free to ask.

 

Bye Dandu

 

Hi.

 

I have made changes to the map, which by the way runs great. The problem is that I keep getting error 54 (suspect CRC problem). I have modified the 3:rd last byte to make the same checksum8 as before (0xFA) - to no avail.

 

The stock map is located at http://wintermute.csbnet.se/~zilog/originalmapp_jaz.BIN

and my modified map at http://wintermute.csbnet.se/~zilog/modmap_jaz.BIN

 

Anyone have any hints on this?

[Dandu 0]

Hey zilog,

 

it's nice to hear, that your adjustments have been successful - leaving out the checksum problem. I'm going to take a look at both files soon ... let's say at the weekend. If somebody is faster, he is allowed to step forward.

 

Bye Dandu

[jackherer 543]

it's nice to hear, that your adjustments have been successful

 

It certainly is, its also nice to see them publicly documented as opposed to being treated as trade secrets, thank you very much Zilog

 

An appropriate username for this thread too