Toyota is recalling 700,000 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.
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.
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.