I was driving the vehicle with 2 other occupants onboard on [XXX] towards US-101. The EPS warning light already came on after entering [XXX] from [XXX], but initially, I didn't think it was much of an issue. As I merged to the right lane in preparation of entering the highway, the steering began to feel very stiff, so I immediately made a right turn into a local street when there was a little bit of steering left. As soon as I pulled over, the steering locked up completely, and both the EPS warning light and the dash display's lane-departure system warning were activated. Luckily no other vehicle or humans were endangered at the time. I put the car into park and powered it off. When I powered it back on again several minutes later, the issue resolved itself and I was able to continue driving with normal steering, and steering remained normal after several power on/off cycles which included both local and highway driving. Come to think of it, ~3 months before this incident happened, I already noticed occasional stuttering of the steering wheel and humming of the EPS assembly when the car is stationary or at low speed. I took the car to a third-party repair shop on the next day since the Hyundai dealership appointment is a week away at the earliest. They ran diagnosis before telling me that the steering sensor in the EPS motor assembly failed, and this happened very frequently for 2017 Sonata Plug-in hybrids. This happens so often, apparently, that Hyundai issued service bulletin [XXX], but this very much looks like a recall to me, as when the system fails, steering is lost completely, and could cause great harm to myself as well as the occupants onboard, not to mention other vehicles around me. I was lucky that it happened before I entered the highway and also had a place to pull over. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
NHTSA ODI 11568255