The contact owns a 2017 GMC Yukon XL. The contact stated that the vehicle was previously repaired under NHTSA Campaign Number: 19V645000 (Service Brakes, Hydraulic); however, the failure occurred after the recall repair. The contact stated that while driving at an undisclosed speed, the brake pedal was depressed and went to the floorboard. No warning light was illuminated. The vehicle continued to move forward and rear-ended the vehicle ahead. There was no air bag deployed. There were no injuries sustained. A Police report was not filed. The contact stated that there was damage to the front bumper. The vehicle was driven away from the crash scene. The vehicle was taken back to the dealer, and the failure was associated with the recall. The contact stated that an unknown module needed to be replaced, but the manufacturer had to authorize the repair. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 170,000.