checksums

[neilmch]

Does the checksum need to be the same on every file you modify and load to your ecu, so your ecu will be looking for 12345abc (exact same checksum as origional file) to know the files good?

Or does the checksum differ on every file and is not specific to that ecu?

Thanks

[br556hre]

checksum is a value used to verify the integrity of a file or a data transfer, so it cannort be the same for modified data.
Anyway there can be multiple levels of checksums.. just google about it, read and you will undserstand.

[xlinuxasx]

Is it possible that my car doesnt start after installing tuned file with winols checksum, but Im installing it via Mpps, wich does its own checksum?

[bobolin4o]

Is it possible that my car doesnt start after installing tuned file with winols checksum, but Im installing it via Mpps, wich does its own checksum?

It depends... what car?

[xlinuxasx]

Passat b6 2.0tdi 103kw bmp engine

[bobolin4o]

EDC16U34... with ori file back it starts?

[xlinuxasx]

Yep, original is all ok

[bobolin4o]

so, disable all checksum correction (with restore original data) in your winols and flash it again... you will see...

[xlinuxasx]

Damn, It didnt work

[bobolin4o]

Have other tool?
When you want to flash... MPPS ask you if you want checksum correction, or not?

[xlinuxasx]

No, just winols and just Mpps to install.
Mpps dont ask for checksum.
I have another tuned file, and it works after install. Maybe its something wrong with tuned file

I see in winols that original file has potential 209maps, and tuned 211maps. Maybe its bad file or something

[bobolin4o]

No, just winols and just Mpps to install.
Mpps dont ask for checksum.
I have another tuned file, and it works after install. Maybe its something wrong with tuned file

I see in winols that original file has potential 209maps, and tuned 211maps. Maybe its bad file or something


So... you answered yourself to your question... your file is other software version. You are lucky, that you didn't "kill" the ECU with it!

[xlinuxasx]

Yeah, thanks for help!

[neilmch]

I have been reading google to understand what has gone wrong with a file i wrote. From what i gather the checksum is a way of the ecu verifying that the code is correct, if it doesnt add up to the sum its looking for it knows that data is missing or corrupt. My origional file has a different checksum to the files written after,

So just to clarify the checksum can be different on a written file to the origional?
The ecu will use the new checksum to calculate if the data on that file is correct, so as long as all the data lines in that file have correct checksums the ecu will like it?

[bobolin4o]

So just to clarify the checksum can be different on a written file to the origional?
The ecu will use the new checksum to calculate if the data on that file is correct, so as long as all the data lines in that file have correct checksums the ecu will like it?


1. Yes, the checksum can be different.
2. Yes, that is the point of the checksum at all.

Will be good if you post both files, so we can check if there is something wrong...

[neilmch]

1. Yes, the checksum can be different.
2. Yes, that is the point of the checksum at all.

Will be good if you post both files, so we can check if there is something wrong...

The file has been checked and corrected by another forum user and re written to the ecu, vans running again. Only one tuning tool out of many would re load a bdm to the ecu and that was a old galleto tool. The problem is the ecu still refuses to communicate through obd and bdm with other tools. I dont have a original unmolested bdm file for this ecu now only a bdm read after a modded file was loaded through obd at first try. I have a original obd read file.

From what i can gather you cant load a obd through bdm it has to be full good bdm read file (?), so what im trying to work out is if i can somehow get the files merged into one, so the modded obd part taken off the bdm file i have and replaced with my origional obd read file making a good origional bdm file, this bdm file then loaded back on with the galleto tool. Hopefully bringing my ecu back to how it was and no longer refusing to comunicate through obd and start the tuning from scratch. (hope this makes sense)

The checksum question is me trying to work out if all this is possible, if the 2 files can me merged somehow.

Any thoughts?

Thanks:cheers:

[bobolin4o]

Mate... if you really need some help - post your files with explanation of them.
Otherwise - contact again to this "another forum user" and speak with him.
How do you think... i want to steal your job, or i want to HELP you?

[neilmch]

Sorry mate i didnt post them as i was changing the vacuum pump on it so in and out of the house. Im not a tuner, just working on my own vehicle.

heres the files, crafter reading1 is my original obd read file, crafter ori BDM is the bdm with a modified obd file on (this file is the problem as its blocked writing and also seems to have blocked EML from all faults)

Thanks

[bobolin4o]

Here is a file with a good EGR and DPF off.
Flash it BDM, let the tool to calculate the checksum.
Start the car and leave it to work 1 hour.
After that you will be able to read it OBD.
Regards!