I initially had a tune done with HP tuners at my friends shop. Now every time we try to make adjustments or do anything else it fails during the validation phase of communicating with the computer. I've changed the PCM twice and it still does the same thing, the only thing that has changed is the radio. Unfortunately I cannot find my stock radio now. I'm ready to ditch it and go carb and th400, i'm currently driving around with electric fans that I just installed that I can't turn on the PCM because of this issue.someone help please.

 

Can you pull the program from the PCM?

 

The remote starter in my wife's Tahoe also interferes with tuning communication , I have to pull the fuse the brain box on it .

 

No it fails when it try's to validate the PCM during communication so I can neither pull the program or make any changes to it. It does allow me to view the diagnostics and gauges so it is communicating I just can't change anything in the tune whatsoever

 

Also I do not have remote start, or really too many features this is a stripped-down work truck model with power windows and door locks. It worked great in the initial tune that's why I'm thinking it's possibly the radio??

 

Yes that's what I'm getting at , take the radio out of the equation.

And yes the remote start interfere's exactley the same way as the issue your having , that's why I posted , I know you don't have RS , but kill your radio and see if it works .

 

I located the stock radio, so it will be going in tomorrow as it was for the initial tune, hopefully that works. Will let you know, thank you for the replies

 

I had a similar issue and thought my PCM was bad also, I tried a spare PCM I have and still couldn't upload tunes. I had to think back to what changed in the last month since the last tune was uploaded and it turned out to be a USASpec iPod adaptor I installed that goes between the stereo and the satellite radio. I have to unplug the adaptor whenever I want to upload a new tune.

The fact that you said the only thing you did was change the radio makes me think it could be related.

 

Switched radio and now hp tuners is saying no power at the cord, fails immediately.less progress then before.

 

Reset battery, computer, everything...now working. The radio is it