The contact called on behalf of his mother who owns a 2015 Toyota Sienna. The contact stated while his mother was driving 15 MPH, the brake pedal was depressed but failed to respond, causing the vehicle to crash into the rear of another occupied vehicle. There was no warning light illuminated. The air bags did not deploy. Both the contact's mother and the other driver received assistance from emergency units. The contact's mother sought medical assistance and was informed that she had sustained soreness in the neck muscle. The contact was unsure whether the other driver sustained any injuries. The vehicle was towed to a tow lot. The vehicle was then towed to an autobody shop but was not repaired. The vehicle was then towed to the residence. A police report was filed. The dealer and the manufacturer were not notified of the failure. The vehicle was not diagnosed nor repaired. The failure mileage was approximately 93,955.