Holden / Pontiac TCM Checksum errors

I've just started working on a VZ Clubsport LS2, T42. Just got thrown by this error message which I've never seen before tuning with Flashscan. Going through the normal procedures > IGINTION ON > click READ CALIBRATION DATA > select T42 CONTROLLER > click CHECK STATUS (result OK) > click START.

Once Flashscan has completed reading the T42 and after the 15 seconds countdown has finished, this message appears:
http://nqhsvls-1.com.au/efilive/t42-checksum.jpg


Looking in EFILive tune screen you can see the checksum errors:
http://nqhsvls-1.com.au/efilive/t42-tune.jpg


So I click on the UPDATE CHECKSUMS and get this lovely message:
http://nqhsvls-1.com.au/efilive/t42-warning.jpg

I've read the PLEASE NOTE and sounds exactly right for my situation but not seeing this error before and not seeing any mention on the forum I thought I would post to ensure it's fine for me to UPDATE CHECKSUMS.

Cheers,
Brett

The Holden T42 calibrations checksums are wrong from the factory - we don't know why.
Yes it is fine to correct them, in fact you MUST correct them or EFILive won't let you flash the TCM.

Regards
Paul

Another instance of GM being weird, huh?:bash:

Thanks for that, I was 99.9% sure that was the case.

Someone needs to run a spell checker through those bits of the code me thinks.

DO NOT PRECEDED WITH OPERATION.

incorrect and/or disbaled checksums.

:lol:

Quote:

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Originally Posted by Tre-Cool

Someone needs to run a spell checker through those bits of the code me thinks.

DO NOT PRECEDED WITH OPERATION.

incorrect and/or disbaled checksums.

:lol:

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Doh!

Wow Paul, when did you type that one up?, 3am after some Jack and Coke?

Cheers,
Ross

Quote:

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Originally Posted by GMPX

Wow Paul, when did you type that one up?, 3am after some Jack and Coke?

Cheers,
Ross

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I'm beginning to wonder... But you know what they say, you can program or you can spell, but you can't do both.:bash:

You don't need to know how to spell to program CPU's, but nothing is written in English anyway. People in the 'real world' just don't get it when you get change from a shop and you complain about a divide by zero error.

Cheers,
Ross

does the checksum really matter? I just did a 99 vette tuned by a known tuner a few years ago and they disabled the checksum because they rewrote a 411 to run non DBW. I actually had to read it with other software and force a 896 file into it before efilive would even get past the bootloader. efilive kept telling me the bootloader was locked but it was'nt. now the pcm is happy. one thing that did come out of it was every time the battery went dead the car would not start until it was sent to the tuner that origonally tampered with the pcm. so the question will an incorrect checksum stop a car from running?
Dana