Toyota announced at the end of June that it will begin to recall over 80,000 hybrid sport utility vehicles. The two models affected are 45,500 Highlander Hybrids and 36,700 Lexus RX 400H SUVs made in the United States between 2006 and 2007.
The defect is centered around the circuit board of the new “Intelligent Design Module” (IDM). The IDM is a key component in the SUVs’ hybrid gasoline-electric power systems. Some of the transistors on the IDMs’ control boards weren’t soldered right. As a result, under certain conditions, the IDM transistors may not be able to withstand the heat produced by the high electrical current.
According to Toyota, if this were to happen, a dashboard warning light would come on. More times than not, the SUV will enter “fail-safe driving” mode, in which the vehicle can still be driven short distances with low power. However, the power supply circuit’s fuse could blow, shutting down all power.
Toyota plans to send letters by mail in mid-July to notify affected vehicle owners of the faulty condition. After it has enough parts, Toyota will begin making service appointments with customers to inspect the Intelligent Design Modules and have them replaced, if necessary.*
*Toyota’s parts-supply network was damaged by the March earthquake and tsunami, and has yet to fully recover from the aftermath.