The contact owned a 2021 Volkswagen ID.4. The contact stated that while driving on a highway at a moderate speed, traffic came to a sudden halt. The vehicle's forward avoidance collision feature was activated; however, the feature did not perform at full capacity and hesitated to fully stop. The contact repeatedly pumped the brake pedal; however, the vehicle independently accelerated and crashed into the vehicle ahead which resulted in a five-vehicle accident. An unknown red warning light appeared on the instrument panel during the failure. The air bags deployed upon impact. Upon air bag deployment, the contact sustained burns to the left thumb and chest; additionally, the contact experienced soreness to the cervical spine, neck, both knees and ankles. The driver of the vehicle which the contact directly hit also sustained a sore neck but neither driver sought medical attention. The vehicle was towed to an independent mechanic where the vehicle was deemed a total loss. Before the accident, the contact stated that a software update was performed on the vehicle which changed the vehicle's driving performance. The contact also noted that while driving at 70 MPH after the software update was performed, the vehicle independently accelerated without depressing the accelerator pedal. The contact was not certain if any warning lights appeared on the instrument panel during the failure. The dealer nor the manufacturer had yet to be notified of the failure. The failure mileage was unkn