NHTSA Complaint #11477826 — 2021 HYUNDAI SANTA FE HYBRID

While I was traveling 70-75 mph the vehicle had a sudden loss of engine and battery output performance and I began losing speed. There was a very rapid decrease in speed, and no warning chime activated per manual. “Check Hybrid System. Stop Safely, triangle warning displayed.” The vehicle would not accelerate despite pressing the gas pedal all the way to the floor and had to be coasted off the interstate through three lanes of traffic to get to the shoulder. No fault indications were present in the Bluelink app despite warnings present on the dash. Mileage was 6506 at the occurrence, vehicle was in Smart. Adaptive Cruise Control and Lane Keep Assist were being utilized, when disabled acceleration did not return. I was advised to turn off the car and turn it back on due to no faults present via remote troubleshooting tools and no dealership within 150 miles, and the vehicle resumed operating okay. After taking it for service at the next available “emergency slot” two weeks later at my local dealership and the car being there for one week, they reported condition could not be duplicated, the vehicle is operating to the manufacturer's specifications. I noted my serious concerns and that a serious safety defect that allows a vehicle to lose all acceleration on the highway and the vehicle not sounding a warning chime can lead to dangerous scenarios on the road and I was assured there was nothing wrong with my vehicle and it would not occur again as it was operating within manufacturer specifications. The vehicle did have a subsequent failure of this same type at a later date. It was not investigated by anyone other dealership. The manufacturer failed to address the loss of acceleration concerns when requested. No chime activated but should have received one per manual. A safety warning was present on the dash, “Check Hybrid System. Stop Safely” service warning triangle. I am unsure how long it appeared before the loss of acceleration due to no chime.