2015 Tahoe LTZ with push to start. Not sure if I noticed it before but read out with latest version of V8. Saved. Turned of AFM and deactivation solenoids only. Licensed and reflashed. Obviously the normal push button routine of fob in vehicle. One press on without hitting brake for key on. Flash finished without issue. Now radio is flickering on and off randomly. Coincidence or something within the flash? I know efi doesn