Unable to read VCM

I have tried HP tuners on two conversion trucks and am unable to locate the VCM on either truck. I can not scan nor read the VCM. Both trucks were built by different people and different companies modified the harnesses and reprogrammed the VCMs. One of the trucks was tuned in the truck using ls1edit. I do not know what program was used on the other truck. I have used 2 different hand held scanners, Predator and Palm, on both trucks and both scanners worked fine.

Now for the confusing part.

I connected the HPTuner laptop to a 2007 Chevy diesel and a 2007 Jeep Wrangler and HPTuners was able to locate the VCM in both of them.

I have check the power and ground at the obd2 connector in both conversion trucks and they are both good.


I have already read the sticky.

Any ideas on what the problem may be?



Thanks,
LVJimmy

Anybody?

The interface was bad. HPTuners asked me to send it to them. They diagnosed it as bad and promptly repaired it and sent it back.. Thanks HP Tuners:):)