Dreadful 12579405 OS.

[Dan Bradley]

Hi. New to the group and this will be my first time tuning. Im running a LQ4 in a suburban 2500 using the 2003 trans. Everything is bolted in but just need fuel lines and tune. Im using LS droid and TunerPro. So I downloaded the OS and it is 12579405. From what I've read is that there isn't a XDF for it yet. Anyone have any updated info on this? Thanks.

[Lifter_annihilator-6]

I am currently working with the same situation. 9405 pcm, little to no experience, ls Droid and obdlink lx. if you figured out a way to swap the osid from 12579405 to the 7603 or similar osid with tuner pro or ls droid please let me know. Thanks

[Lifter_annihilator-6]

Dear Dan,

After combing the interweb and finding the same info on the 9405 xdf being non existant i decided to change OS it and possibly brick the pcm.
I was very weary of trying the 7603 p59 1mb bin and xdf but i decided to swing it and see what happened. After i successfully flashed the 9405 3 times with a base tune the LS droid allowed me to do the OS+Cal flash and sure enough the 7603 combo did the trick. The first hit was a success and I will report any further experience if you would like.

[Dan Bradley]

I've put this on the back burner but need to get this done. I'm going to try the 7603 and hope I get the same out come. Thanks for the help.

[nickdow1983]

i have the 12579405 os how do i go about changing my os like u did

[Dan Bradley]

I downloaded the 7603 by using Tuner Pro and PC Hammer. Tuner pro works but PC hammer has options. I downloaded the 7603 os from hear but it was for a returnless fuel system.