Toyota will be recalling certain Toyota and Lexus hybrid vehicles for a problem with the propulsion system that could lead to the vehicle entering a fail safe/limp home mode. The dirvability of the vehicle could be limited resulting in an unexpected stall, increasing the risk of an accident. Approximately 133,081 vehicles could be affected by this problem.
According to the recall report, the inverter assembly of the hybrid system is equipped an Intelligent Power Module (IPM) which contains a control board with transistors, know as Insulated Gate Bipoloar Transistors (IGBT’s). Due to a variation in characteristics of the IGBT’s built in parallel circuits, higher operating temperatures exceeding the allowable temperature of the lead based solder could occur. The solder could degrade and eventually cause heat damage to the IGBT’s. Drivers may experience various warning lights on the instrument panel illuminating and, in most cases, the vehicle will enter a fail safe mode. In some instances the fuse of the power supply circuit could blow causing the entire system to shut down completely. The vehicles associated with this recall include:
Toyota will notify owners to take their vehicles to their nearest dealer to have the IPM replaced. Anyone wanting more information about the problem can contact Toyota at 1-800-331-4331. Vehicles that had their IPM replaced under a previous recall in June 2011 (11V-342) are not affected by this campaign.