The official notice
Defect
Toyota is recalling certain model year 2010 through 2014 Prius vehicles. In the affected vehicles, the Intelligent Power Module (IPM) inside the inverter module (a component of the hybrid system) contains transistors that may become damaged from high operating temperatures. If this occurs, various warning lamps will be illuminated on the instrument panel and the vehicle will have reduced power allowing it to only drive a short distance.
Safety Risk
The vehicle may enter a fail-safe/limp-home mode that limits the drivability of the vehicle. The hybrid system could also shut down completely resulting in a vehicle stall, increasing the risk of a crash.
Remedy
Toyota will notify owners and dealers will update the software for both the motor/generator control electronic control unit (ECU) and the hybrid control ECU, free of charge. If an owner experiences a failure of the inverter before the vehicle receives updated software, the dealer will repair or replace the inverter assembly with a new one at no charge. The recall began on March 21, 2014. Owners may contact Toyota at 1-800-331-4331.