The contact owns a 2025 Hyundai Tucson. The contact stated while driving 15 MPH and depressing the brake pedal to decelerate, an unknown warning light was illuminated and a beeping sound was engaged. The contact stated that the vehicle failed to decelerate as intended and came to a sudden stop, causing another vehicle to crash into the rear of the vehicle. The air bags did not deploy. There was no injury sustained. The contact was able to drive the vehicle away from the scene. No police report was filed. There was no property damage. The vehicle was taken to the dealer, where it was test-driven, but the failure could not be duplicated. The dealer informed the contact that they had turned off all the sensors, except for the rearview camera sensors, to prevent the failure from reoccurring. The vehicle was diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 760.