I have a 2014 Terrain tried to tow behind a new Tiffin Wayfater, all within weight limits.Had the “Death” wobble develope @ 56/57 MPH with & without #32 fuse pulled, experminted weather or not power steering was active with the # 16 fuse was pulled, no difference at all, power steering was never active through any of these test. I”m actually afraid to do a road test. The above Terrain is 6 cyl 2WD good condition with 55,000 mi. I have owned 7 motor homes over 44 years, towing behind all of them. This Tiffin is the smallest and the most concerning experience I have ever had. The reason I chose Terrain, I have owned it for several yrs.y wife and I are older now and wanted a vehicle easy to get in and out of etc. etc.
I share all of this just to say I don’t think there is a for sure a fix found yet and is a very serious condition.