The contact owns a 2023 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed on several occasions, the pedestrian warning alert unexpectedly illuminated. The contact stated that during the failure, the braking system became inoperable and then the brakes locked up, causing the contact and a passenger to suffer whiplash. The contact stated that there were no pedestrians near the vehicle when the failure had occurred. Additionally, the contact stated that while attempting to reverse, the pedestrian detection system failed to display a warning when a pedestrian was near the vehicle, almost causing the vehicle to strike the pedestrian. The vehicle was taken to the dealer, where the contact was informed that the failure was related to an electrical anomaly and a hardware failure. The contact was advised that an over-the-air update might be issued to address the issue. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 12,000.