I have a 2012 Chevy Suburban LTZ the liftgate stopped working not too long ago and I think the dealer said it was just a setting that they turned back on when I took it in for service on something else. It is not working again after I took it in for a car wash and they wiped things down. Where is this setting to turn the automatic on the liftgate back on?

 

The button that you press to open the liftgate inside the truck, (up above the rear view mirror) has a dot on it. If it's pressed, that is in the "off" (or manual) position. Make sure it's not turned off.