Help please GMC every 2nd flash comes up pinned out.

I have a GMC 2003 5.3l every time I go to do my second flash to the ecu comes up pinned out then I have to wait 2 3 hours with battery disconnected to reflash the ecu. Engine battery is new cables all connected and battery in laptop fully charged. Please if anyone knows any suggestions please let me know. Its only with this one car i have no problems with any of the other cars. Thank you

hp tuners