0411 PCM ?writer Transfer: x7F Negative Response Code?

[BigEd]

I also downloaded a tune from the repository to try changing the vin and engine to
a 4.8L (which is the engine I have) and I can not get it to write with that either. (cost me 2 credits for that file)

HP Tuners says:

Hardware: P01 ECM, GM Gen 3 v8, 4.3L V6
Operating System: 12208322

Any ideas or suggestions by anyone?
I have made my own programming station for doing this inside since it is so hot outside.

I am wondering if someone has used a handheld programmer on it and that is why I cant write to it??

I have already emailed Customer support regarding this.
But it being late at night I doubt I will hear anything til around lunchtime tomorrow.

[RandomEnthusiast]

You might have a locked pcm.

[BigEd]

I figured out that my desktop plug was missing 2 wires. one for battery and one for the ignition.

once I got those hooked up, it worked fine.

Now I am trying to read a file from an 05 PCM and according to all the info I have its the same wiring for the red plug. But I am not getting a response.