I just had the same problem with my 3 month old Santa Fe Northern. Last night, it started operating very erratically.....sudden stops, garbled chuffing etc. Then it wouldn't respond to commands. I suspected a drawbar problem, but as it turns out, it was on the engine side. The engine has the same kind of plug and it's hard to see. You have to remove the shell to properly access it. The plug was not seated all the way down. Squeezed it with small pliers and now it works. I hope.
Roger