Write Calibration fails after Erasing VCM on LLY Duramax

[LS6FD]

Hello,

I'm at my wits' end with this issue. About 95% of the time when I try to write calibration on my 2005 LLY Duramax, it will fail after the Erasing VCM step then say that it can't find VIN if I try again (I'm writing in low speed mode). The only way I can continue is to pull the VCM fuse and let the computer reset. I emailed support about this and the person that responded said it's probably a wiring issue with the truck. I just don't believe this. I run the Edge CTS monitor which hooks up to the OBDII port and it has never had a glitch reading data. I can also log data just fine with HP Tuners. I would think that if there was some wiring issue with the OBDII connections, I would not be able to read data perfectly ALL the time. When the write fails, the computer acts like it resets--the gauge lights blink, there's an audible click sound, and the door chime sounds again as if I just turned the ignition on. It seems like there's something in the truck's systems that gets reset and causes the data connection to be interrupted/broken. I have pulled the OnStar fuse since I've read that it can cause problems. Maybe there's other fuses or something I need to pull, I don't know.

I have also tried writing in high speed mode but have never had that succeed--it fails on downloading bootloader.

This morning I was trying to write another calibration and had the same issue. However this time after pulling the fuse I'm still getting the error that it now can't find the VIN and I can't crank my truck which leaves me quite nervous that I've screwed up my VCM.

I got the latest beta (as of a week ago or so) to see if it would help but it made no difference. It did seem to do a firmware update on my MVPI interface the first time I used it.

Any help would be much appreciated.

*EDIT -- Oops meant to post this in the VCM Help section. If a mod can move it please, that would be appreciated :-)

[waynehartwig]

Do you have an aftermarket radio?


This is how it works. When you tap into the OBDII port and want to read/write to a module, that module will send a 'shut up' signal to every other module on the line. If you have an aftermarket item on the line, such as a radio or remote start, they will not 'hear' the 'shut up' signal and keep talking. Thus causing the read/write to fail.

[miker2]

maybe,its that edge monitor .

[Gerrot]

Any update on this problem? I'm having the same thing!

[Keith@HPTuners]

OP hasn't visited this forum in over a year, so it's unlikely we'll know what solved his issue.

[Gerrot]

Anyone else out there have this problem?

[American-Thunder]

Anyone else out there have this problem?

I'm have this exact problem if anyone ever figured out a solution. Just posted it to https://forum.hptuners.com/showthrea...-fail-to-write