Can't read VCM

[braap]

Anyone else had this problem? The vehicle in question is a 2004 Silverado with a 6.6 liter LB7 diesel. I have the MPVi pro interface with the latest version of HP Tuners. I can connect with VCM Scanner just fine, but when I try to "read entire" it stops at the "Preparing VCM" step and comes up with this error: "Boot Loader Download request timed out".

It was suggested that the truck may have a tune on it already and is possibly locked. Knowing that, I took it to the dealership for a reflash and the tech was unable to do so using his Consult programmer.

Any ideas, guys?

Thanks,
Steve

[vette_doc]

if you are able to scan your truck with hptuner then your vcm is locked by an other tuner,if not then check your cigrette lighter fuse.

[Bill@HPTuners]

Make sure you remove any inline modules ie banks, edge, etc.

Try doing the read in low speed mode.

If all else fails contact support@

[braap]

vette doc: The cig lighters are all good. I bought the truck used, so it's impossible to know if the previous owner had a tune put on it, but it seems to be a likely possibility.

Bill: done.

Thanks, guys.

[vette_doc]

if you know somebody who has tech2, let him flash your vcm, if he will be unable to do so then your vcm is locked and you must buy a new vcm.

[sfogg]

I upgraded my serial interface to the MVPI Pro and now I get the same error on a 2004 GMC Sierra 5.3l.

I bought the truck new and the only tuning that was ever done on it was done by me with HPTuners and I did not lock the VCM.

Shawn

[Bill@HPTuners]

I upgraded my serial interface to the MVPI Pro and now I get the same error on a 2004 GMC Sierra 5.3l.

I bought the truck new and the only tuning that was ever done on it was done by me with HPTuners and I did not lock the VCM.

Shawn

Completely different pcm, completely different tcm, completely different situation.

[FDKLB7]

I have a 2003 LB7 2500HD and when i did my vcm read it got to 33% and stopped and timed out because it failed to connect. That was when it tryed to read the TCM. So when it said waiting 10 seconds to connect to TCM i turned the key off then back to the on position and it was able to connect. Dont know if thats the problem you are having but when i did that it works fine. I have the same issue when trying to write my tunes also so i have to do the same thing with the key.

[Bill@HPTuners]

Try reading in low speed mode.

[1998DaytonaGrandPrix]

I am having this same messege, i REALLY wish they had all previous versions avail for dl in case the current one wont work for every1, cause before I got deployed to Iraq i was using 2.1.18 and had NO probs, I get back and with version 2.22 all I get is Unable to find VCM, 2.23 beta version does the same thing... REALLY FRUSTRATING...

[mz225]

did anyone ever find a fix for this "boot loader download request timed out" error. i'm having the same issue with my 03 lb7. i've tried removing the radio/info fuses, disconecting batteries overnight, unhooking guages and radio and everything else i've read on the forums, but no one has reported back actually finding the problem. bill @ support has been a lot of help but i was hopeing someone else might have been through the same thing and found a solution.

[HSESWS6]

Also wondering if there is a fix or something to look for...

I just had the same problem yesterday on a 2001 2500 Duramax truck and any help would be appreciated.

[thunderbolt]

I had this issue with my Duramax truck after installing an aftermarket audio system. (Sony DVD/Radio using interfaces from Peripheral)
Put a switch to kill power to the radio interface module and then I got access to the VCM....