Why's my 2015 GMC Terrain heated seats not working?

The heated seats in Your 2015 GMC Terrain are powered through a fuse in the interior fuse panel. The specific location varies based on the trim and model You have so You will need to look at the diagram located on the underside of the fuse panel cover. If You do have a blown fuse, make sure to replace it with one of the same amperage. If the fuses are all ok or if the fuse immediately blows when You replace it, You most likely have a short to ground in the heating coils which will require replacing the entire heater. If all fuses are good and neither the driver or passenger side works You need to have the front seat heater control module checked, this seems to be the most common issue.