Checksum Error Question

[780ripper]

Hi Guys, i'm starting to make small tweaks to my truck bin file. I started by adjusting the electric cooling fan on/off temperatures today, and when i saved the changes to a new file name it showed a checksum error. Can someone give me a brief explanation of what this is and how to correct it. Thank you.

[B52Bombardier1]

A bad checksum will brick your PCM if the BIN containing the error is allowed to be written to the PCM. What named BIN file are you using and what named XDF definition file are you using inside of Tuner Pro RT? They need to be the same.

Rick

[780ripper]

The bin and xdf files seem match, OS 12208322 i can open the bin file and look at it, make mods but i haven't written it onto my pcm . I posted the files below if you can have a look and let me know where im making the mistake i would appreciate it.

[B52Bombardier1]

Your XDF file size matches what I have here. What size of engine are you needing? Is it really an 8.1 liter engine that is what you are installing in a vehicle? I'm thinking there may be something already wrong with the BIN you posted above. Not that it was your fault but that somebody had bodged up by using the wrong XDF with it before you got it.

If it is a different engine size that you need, this BIN will require a segment swap.

Rick

[B52Bombardier1]

There are also "checksum plugin" files for Tuner Pro RT. Do you have those from the TP RT web site?

Rick

[780ripper]

hi Rick, yes its an 8.1 / 4L80E that i installed, in a half ton, its awesome. i had a professional tuner set up the pcm with hp tuners so that i could run, from what i can see he mostly just removed the vats and my cash. I also bought a professionally assembled wiring harness that turned out to be missing connections which i also had to sort out bu myself. Im in the process of installing fuel pressure and air fuel ratio gauges so that i can watch what its doing. It runs hot so i want to change the fan settings for starters. I do not have the checksum plugin for that file, and i don't know how to use it yet, steep learning curve, i was hoping to make a clone of my pcm just in case i screw it up. i have a second pcm with OS 12216125 also set up to run this truck but it doesn't work properly

[B52Bombardier1]

What hardware are you using to do the reading of your PCM? I recommend the use of a Bluetooth "OBDLink MX+" device and either "PCM Hammer" as a Windows program of "LS Droid" as an Android program. Either of these with the MX hardware can make you a clone copy and I recommend the use of a bench harness.

Where did you get a copy of the BIN file you are working on?

Is it possible that your tuner person "tuner locked" the tune inside your PCM?

Rick

[780ripper]

hi Rick, i am using tuner pro v5 and pcm hammer 14 along with OBD link LX. I have read every pcm that i have available to me on the bench with this set up and it all worked. When i open the tune with hp tuners ( the program that was used to first tune my pcm) to view it it says that its not locked. The bin file is directly from what is on the pcm that is running my truck.

[B52Bombardier1]

This makes no sense to me. You say you are using a BIN file in the first post above but you open the tune with HP Tuners. But . . . HP Tuners does not presently have a capability to open a BIN file . . . only a *.HPT file. So I'm lost here.

Rick

[LRT]

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[780ripper]

Hi LRT, thank you for the great info here,
you hit the nail on the head, im very new and still learning and overwhelmed with all the information available. I have spent countless hours to get this far and will probably spend countless hours more to learn and i dont expect to get it right over nite.

I am grateful that someone took the time to write this tuning software because its free but more because its interesting and requires educating and challenging yourself. I am also grateful that this forum exists and that there arre ppl like yourself and B52 to guide someone like me.

I started this project about 2 years ago and have gone from not knowing a thing about the efi system on my truck to doing a complete engine trans swap, redesigning the frame cooling system and wiring and now reading the pcms that i have.

To answer your questions:
yes i read the instructions in post 1 doesnt mention checksum use? only that is should be in the plugin folder.
I first built the test cable and read all of my pcms to determine which pcm has which os and data on it
i did download the checksum but did not use it correctly?
the xdf file is from the tunerpro website not from the post on here, i now downloaded the suggested files
i matched the xdf file to the pcm to the os
the bin file is directly from my vehicle as left by someone who tuned it previously with hp tuners, i opened both programs and compared the data in the tables between the hpt and tunerpro files
i have everything downloaded into one folder but i did not actually see instructions on how and where to install or use the checksum portion, maybe some guidance here please,

Hi rick, to explain better, i have a trial copy of hp tuners that i used to open the hpt file for my pcm. I did this to compare the data in the tables between hptuners and tuner pro, for my own self interest, and to verify things are not locked before doing tunerpro work. Sorry i didnt explain this very well,

[780ripper]

so i went back and did everything from the beginning as instructed in post 10. i adjusted the fan cut in and cut out temps and delays just like i wanted and saved the new file with a different name again but this time no checksum error message.does this mean that the bin file that i just saved is safe to write to the pcm?

[LRT]

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[780ripper]

thank you for checking, please see attached

[LRT]

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