The first recalls for Toyota’s widely respected hybrid drive system came in 2011.
Toyota Motor Sales U.S.A. is recalling 133,000 2006-2010 Highlander Hybrid models and 2006-2008 Lexus RX 400h crossover SUVs for a safety defect that causes the vehicles to shut down without warning and go into the so-called “limp home” mode. Previously, Toyota recalled some of these hybrids for the same problem in 2011. (Toyota Recalls 80,000 Highlander Hybrid and RX 400hVehicles)
In the involved Toyota Highlander Hybrid recall that also covers Lexus RX 400h vehicles, transistors within the hybrid inverter assembly can experience heat damage “due to variations in characteristics of the transistors built in parallel circuits,” which in Toyota’s disingenuous view is different from the previous recall for the same problem.
In Toyota’s original legally required filing with the National Highway Traffic Safety Administration (NHTSA), the Japanese company said that the so called Intelligent Power Module (IPM) located inside the Hybrid System Inverter contains a control board with defective transistors. Transistors on the control boards in some of 2006-2007 model year Highlander Hybrid and Lexus RX 400h SUVs were “inadequately soldered” and could be damaged from heat caused by a large current flow during high-load driving. In some instances, the power supply circuit fuse could blow when the transistor is damaged. If the fuse blows, the hybrid system will stop and the vehicle will coast to a stop.
Toyota along with Ford Motor Company has the dubious distinction of paying record fines to NHTSA because of cover-ups of known safety defects. The brief Toyota statement on the latest safety recall does not provide accident or fatality details or any information on how the safety defect came to be known. (Ford to Pay Record $17.35 Million NHTSA Fine on Recall)
In a separate safety defect and quality control problem, Toyota also said it is recalling102,000 2006-2011 model Lexus IS 350, IS 350C, and GS 350 vehicles. The bolts used to attach the variable-valve timing control system can loosen, causing the Lexus to stop suddenly while being driven. Toyota claims that an early warning for this condition can be an abnormal noise just after start-up.
