The contact owns a 2016 Ford C-Max. The contact stated that while driving at an undisclosed speed, she heard an abnormal sound emanating from the engine compartment, prompting her to discontinue driving the vehicle. No warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the transmission. The contact was informed that the transmission would need to be replaced. The vehicle was not repaired. The contact stated that the transmission had previously been replaced 3 years prior. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA hotline for assistance. The failure mileage was 49,000.