The current software for the motor/generator control and hybrid control ECUs can cause high heat to develop around some transistors and damage them. If this happens, lights on the dashboard would warn drivers. However, in some instances the problem could result in a failure of the hybrid system.
Dealers will upgrade the software for both ECUs to fix the issue, and Toyota will notify owners in the US by mail about scheduling repairs. According to Reuters, there are also 340,000 vehicles in Japan and 160,000 in Europe that need this, as well.
Toyota's popular hybrid has been subject to at least two other recalls in the US in recent years. One was to adjust the Occupant Classification System for the 2014-2015 Prius V. The other was for an ECU software issue in the 2010-2014 Prius.
July 15, 2015
TORRANCE, Calif., July 15, 2015 – Toyota Motor Sales, USA, Inc. today announced that it is conducting a safety recall of approximately 109,000 Model Year 2012-2014 Prius v hybrid vehicles.
In the involved vehicles, the current software settings for the motor/generator control ECU and hybrid control ECU could result in higher thermal stress in certain transistors, potentially causing them to become damaged. If this happens, various warning lights will illuminate and the vehicle can enter a failsafe mode. In rare circumstances, the hybrid system might shut down while the vehicle is being driven, resulting in the loss of power and the vehicle coming to a stop.
Owners of the involved vehicles will be notified by first class mail. Toyota dealers will update the software for both the motor/generator control ECU and hybrid control ECU in the involved vehicles.
Information about automotive recalls, including but not limited to the list of involved vehicles, is subject to change over time. For the most up-do-date Safety Recall information on Toyota, Lexus or Scion vehicles, customers should check their vehicle's status by visiting toyota.com/recall and entering the Vehicle Identification Number (VIN). Safety Recall inquiry by individual VIN is also available at the NHTSA site: safercar.gov/vin. For any additional questions, customer support is also available by calling Toyota Customer Service at 1-800-331-4331, or Lexus Customer Service at 1-800-255-3987.