I still have not been able to get tuner to connect to my Hummer I have radio pulled and PAC5 unplugged onstar unplugged amp fuse pulled and brake controller in plugged. But I’m not sure this controller is what I need if I have to disassemble my truck every time I want to change from Tow to Economy ...

I just received the tuner Monday and I have updated it now I have tried several times to connect and everytime it has a failure and restarts tuner. Once it set the CEL and I had to use my scan tool to reset code was lost connection to throttle control module.