405 ecu checksum problem?

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RaimoHal
Posts: 13
Joined: Tue Apr 08, 2014 12:22 pm

405 ecu checksum problem?

Post by RaimoHal »

Hi guys,

So i was getting ready to tune M50B25 again and wasnt expecting any problems. I have tuned 402 ecu-s in the past and used ostrich 2.0 with success. This time i was trying to tune 405 ecu, but i could not get the car to start and i think the problem is with the checksum calculation.

Things i have tried:

1. Engine works with stock chip
2. Engine works with stock chip inside the different 405 ecu
3. Engine does not work with stock software uploaded to ostrich
4. Engine does not work with the tune thats been modified and burned to the chip. (i just added +1deg ignition timing to test)
5. Engine works when stock software is burned to different chip.

Im using 405/951 soft XDF

<datastart>0x69FE</datastart>
<dataend>0x799C</dataend>
<storeaddress>0x799D</storeaddress>
<calculationmethod>0x0</calculationmethod>


Has anyone elseexperienced the same issue? Please help!

-Raimo
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RaimoHal
Posts: 13
Joined: Tue Apr 08, 2014 12:22 pm

Re: 405 ecu checksum problem?

Post by RaimoHal »

Edit:

I compared both stock and tuned files side by side in winols and found that the only changes are ignition value that i changed for testing and the checksum values at 799C, 799D and 799E.

On 402 ecu it corrects checksum values only at 2 places..
olafu
Posts: 186
Joined: Tue Jul 26, 2016 12:35 pm
Location: Finland

Re: 405 ecu checksum problem?

Post by olafu »

What happens with no checksum correction in XDF?
I tried to save .bin without any modifications and "BMW_dme405_soft951.xdf" will change the checksum anyway. So i think there is something wrong with checksum calculation, or there is something wrong with stock file "BMW_405_1740352_1267357951.bin"

What is the chip type in 405 ecu? is it 512k (64kB) or 256k (32kB)?
This "BMW_405_1740352_1267357951.bin" is 32kB looks like it's same file 2 times in a row and it should be 32kB file... :?

EDIT: accidentally swapped 512 and 256k conversions. Now corrected.
Last edited by olafu on Sat Jan 22, 2022 3:26 am, edited 1 time in total.
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RaimoHal
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Joined: Tue Apr 08, 2014 12:22 pm

Re: 405 ecu checksum problem?

Post by RaimoHal »

I will try to disable checksum and see if the xdf still wants to correct something.

The chip itself is B58038 = 27c256 = 32kb. I didnt use the file "BMW_405_1740352_1267357951.bin", but it does look like there are two files in a row to make it 64kb.
Last edited by RaimoHal on Sat Jan 22, 2022 1:46 am, edited 1 time in total.
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RaimoHal
Posts: 13
Joined: Tue Apr 08, 2014 12:22 pm

Re: 405 ecu checksum problem?

Post by RaimoHal »

I disabled the checksum and the file was not corrected.

But i did found a mistake in the XDF code. <EMBEDDEDDATA mmedaddress="0x799C" is supposed to be <EMBEDDEDDATA mmedaddress="0x799D". But that address is only for viewing, so i doubt it matters.
olafu
Posts: 186
Joined: Tue Jul 26, 2016 12:35 pm
Location: Finland

Re: 405 ecu checksum problem?

Post by olafu »

But if your bin file has address spacing up to 0xFFFF it is 64kB file, so it couldn't never come out from a 256k chip.
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RaimoHal
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Re: 405 ecu checksum problem?

Post by RaimoHal »

Here is the stock tune file for you to see if you have time:

https://www.upload.ee/files/13817304/St ... 5.rar.html

This is how the file ends:
Image

to compare, this is how 402 ends:
Image

This must be a 32kb file..
olafu
Posts: 186
Joined: Tue Jul 26, 2016 12:35 pm
Location: Finland

Re: 405 ecu checksum problem?

Post by olafu »

What XDF you are using to edit that bin? Chip number in this rar file was 1267356548.
olafu
Posts: 186
Joined: Tue Jul 26, 2016 12:35 pm
Location: Finland

Re: 405 ecu checksum problem?

Post by olafu »

Checked:
XDF for -951.bin will mess the -548.bin file, because in -548.bin the checksum is in different address. Data end = 0x7BF7, store address = 0x7BF8.
Looks like XDF for -951.bin fits at least partially, ignition tables and fuel tables seems ok, so change that checksum address and keep in mind you are using XDF for different bin file.
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RaimoHal
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Re: 405 ecu checksum problem?

Post by RaimoHal »

Today i tested it and it worked!

Thanks!
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