2005 caddy cts-v locked vcm Please Help

[Slick 68]

ok so i was going to put a little more fuel and timing in my cousins cadilac, which i have a license for and have tuned a few months back. we data logged a pass. i edited the program, went out to the car to Write Entire, and it failed validating the vcm. now the car has activated a security system and it wont gather any of the vehicles information. it keeps saying Unable to locate the vcm. The car will not start. Turn the key on and the fuel pump comes on. it will not crank. navigation says theft system. We have tried both keys. It will not let me read the vcm either. any ideas? Please post anything, i need HELP. Thanks

[murphinator]

maybe disconnect the battery for a while and try again ? hopefully someone can be mere helpful but until then thats what I would try - cant hurt

[Bill@HPTuners]

My first question is what is the reasoning behind doing a write entire on a vehicle with an LS1 pcm?

[Slick 68]

this is what i have read on here for the v and i was told to do by someone who has tuned these before. i have previously tuned this car this way too. I have tried deleting my vcmsuite.cfg file. it is still saying unable to locate vcm. it wont connect to the scanner either. All the idiot lights come on with the key. the fuel guage does not come up. everything else seems normal, it just wont crank. we have now disconnected the batt and pulle the ecm fuses to try again in a few mins. Any other info?

[SkullV]

My 2005 CTS-V is SUCH a pain in the ass to tune. EVERY time I try and write the PCM there is a problem. I eventually get it to work, but never the first time. Anytime I try to write calibration only it fails, and 90% of the time I do a write entire it can't get through the erasing the entire PCM part. The last tune also tripped the T/C light for some reason but I disconnected the battery for a half hour and that went away.

I will say that I think the last time it was a battery problem. I tried the write entire again with a charger on the battery and it worked fine.

[Bill@HPTuners]

this is what i have read on here for the v and i was told to do by someone who has tuned these before.

Sounds like bad advice to me.

i have previously tuned this car this way too.

Thats great but by doing so you are risking frying your pcm everytime you do so. Wouldn't you feel more comfortable by not risking your pcm?

I have tried deleting my vcmsuite.cfg file. it is still saying unable to locate vcm.

Whats that supposed to do exactly? deleting the cfg file shouldn't do anything in your case...again probably bad advice or your trying to apply something for some other application to yours which ISN'T THE RIGHT THING TO DO!

we have now disconnected the batt and pulle the ecm fuses to try again in a few mins. Any other info?

I guess, hopefully the pcm isn't fried.

[RomansDesigns]

I have tuned several of these and I had to do a re-write complete vcm everytime.
Mark

[SkullV]

Can someone at HPtuners or a guru on here explain why it is SO hard to get these 1st gen CTS-Vs to take a tune?

[waynehartwig]

I'm interested in knowing why it's a bad idea to 'write entire' on an LS1 PCM? I get that it bricks it, I experienced that first hand - but why?

[SkullV]

Can someone at HPtuners or a guru on here explain why it is SO hard to get these 1st gen CTS-Vs to take a tune?

???

[Bill@HPTuners]

???

The only thing I can think of is some module throwing a hissy fit.

[JonCR96Z]

I haven't done many writes to it, but my 04 V has never had a problem with a 'write calibration'.

[Frost]

I've tuned a half dozen 04-05 CTS V's and have never had any issue just writing the calibration.

[SkullV]

Maybe it's a problem with my computer then. I am running Windows XP on my Mac through bootcamp so maybe it just doesnt like it. I guess I'll pick up another PC laptop for tuning and see what happens.

[Andy0x1]

What were your results?

I have an 05-V and haven't been able to even perform a complete read yet. It seems to sumble it's way through 0.1% at a time... I'll try pulling the Onstar fuse tonight to see if it makes a difference.

[miker2]

magnacharger says to pull the 10 amp audio fuse. fuseblock is under the rear seat.

[Andy0x1]

Well add me to the bricked list.

Strangely I was able to write two sucessful callibrations. The 3rd attempt at a write locked me out of the PCM and now the car is a giant paper weight.

[Andy0x1]

OK spoke too soon. After several failed attempts, I did a Write Entire with "High Speed" disabled. It completed sucessfully and the car is running again.

[ne0c0de]

I have noticed the same in 06-07 TrailBlazer SS and what was doing it was the ONSTAR system.
Either a write entire worked or remove the fuses of ONSTAR on the passenger side fuse panel below. I hope this helps

[ne0c0de]

I have noticed the same in 06-07 TrailBlazer SS and what was doing it was the ONSTAR system.
Either a write entire worked or remove the fuses of ONSTAR on the passenger side fuse panel below. I hope this helps