E67 GMPP controller checksum error

I installed 2 new LS3 installs in muscle cars with GMPP controller kit. The E67 has OS 19211212.

I now have 2 E67 controllers on 2 different cars that have the GMPP harnesses and controllers that give me checksum errors when I read the ECM's. I need to modify the files for the cam changes and to complete the tune on these cars.

It seems odd to have the same problem with 2 different setups. Not too sure if I am doing something wrong. I have not had this issue with other E67 or E38 controllers in the past. I attached the file that I read.

Any ideas?????????

Anyone have a good file?

Looks like GM disabled the checksums in that file, similar to what they did with either a Cavalier or Cobalt SS stage 2/3 reflash (pretty sure Cobalt S/C though).

Can you run the motors with the controllers as they are now? If you can run them on it now, you *might* be ok. If you feel comfortable, you can force the checksums and reflash it back, but I did some quick digging in it and noticed the injector flow rate was all screwy along with a few other things.

I would suggest flashing an OS from a car into it, I know lots of people have done this to bypass this checksum error. They full flash a working Vette, XLR-V, etc tune into the controller and all is good. But you'd have to check the wiring pinouts to make sure whatever tune you use has the same in/outputs as the GMPP wiring.

Quote:

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Originally Posted by ScarabEpic22

Looks like GM disabled the checksums in that file, similar to what they did with either a Cavalier or Cobalt SS stage 2/3 reflash (pretty sure Cobalt S/C though).

Can you run the motors with the controllers as they are now? If you can run them on it now, you *might* be ok. If you feel comfortable, you can force the checksums and reflash it back, but I did some quick digging in it and noticed the injector flow rate was all screwy along with a few other things.

I would suggest flashing an OS from a car into it, I know lots of people have done this to bypass this checksum error. They full flash a working Vette, XLR-V, etc tune into the controller and all is good. But you'd have to check the wiring pinouts to make sure whatever tune you use has the same in/outputs as the GMPP wiring.

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One runs ok. The other has a big cam and will not.

I tried to flash CTS-V file and there is bootblock mismatch. I think that this could cause ETC problems so I stopped the flash.

I really hate to trash the ECM by forcing the flash or forcing the checksum but I need to move forward with something.????????

Sorry for the delay.
GMPP disable the cecksums (who knows why), just correct them with EFILive and you can reflash the ECM. As long as the warning says "Checksum disabled" not "Checksum Error" then you are safe to correct it and re-save the file.

Cheers,
Ross