[timgco]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by LasVegas:
Just bought the Hypertech III. Correct p/n for 03 H2. Followed the instructions to the letter. It starts to read the computer and then gives an error code number and says to restart the hypertech and if it happens again to call them. Of course they're closed for the weekend. I've tried it 3 times with the same results. Anybody else had this problem or can shed some light on this? Thanks <HR></BLOCKQUOTE>

Did you pull your OnStar fuse? And make sure EVERYTHING is off in your truck including your headlights/ DRL's. and try again.