Pre-Collision System (PCS) failed. My daughter during sunset (sun glare) struck the vehicle in front of her, that suddenly braked due to sun glare. Toyota hasn't look at PCS system yet and the car is at the repair shop, but I did open a case with Toyota to investigate failure and access onboard data. Auto repair shop will check the system, but no malfunction warning on the car's warning display. There were no warning present prior to accident or post-accident.