The company has announced a safety recall of the vehicles involving certain 2016-2018 models. The issue at hand is related to a wiring problem that can pose a fire risk:
The subject vehicles have an engine wire harness which is connected to the hybrid vehicle Power Control Unit. A portion of the wire harness could contact the cover at this connection and wear over time, causing an electrical short circuit, which can generate heat. If sufficient heat is generated, there is an increased risk of a vehicle fire.
To find out if your Prius is affected, enter your vehicle identification number at toyota.com/recall. Owners who have an affected Prius model should take it to their local dealership to get the issue fixed. Out of the million vehicles affected, Toyota says 192,000 of them are located in the U.S.