Having an issue with my trans. Just rebuilt the 4l80 month ago. Initially worked fine, now it wont shift out of 1st gear unless you lift off the throttle. If you take off easy it goes through the gears just fine, but if you stand on it outa the hole it wont shift until you lift. Any suggestions greatly appreciated !!!!

 

check all your fuses and make sure you are getting power to the pink wire at the trans plug