The contact owns a 2019 GMC Sierra 1500. The contact stated while her husband was driving at an undisclosed speed with her in the front passenger seat, he noticed that the vehicle in front of his had stopped. The contact stated that her husband immediately depressed the brake pedal, causing the vehicle to forcefully stop. The contact stated that the front passenger's side seat belt pretensioner failed to retract, causing her to hit the back of her head against the headrest. The contact stated that she sustained neck injuries but did not seek medical attention. The vehicle was taken to the local dealer, where it was diagnosed, but the failure could not be determined. The vehicle was not repaired. The contact stated that the failure had been recurring. The manufacturer was not notified of the failure. The failure mileage was 73,833.