One month after Tesla recalled more than 120,000 units of its Model 3 in China, allegedly due to defects in rear motor inverters, the real causes of the defects remain unclear. As Tesla is the first carmaker to use silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) in commercial cars, the recall has sparked debates about the reliability of SiC – the third-generation semiconductor material that is gaining favor.
On April 7, the electric vehicle (EV) maker recalled 127,785 units of Model 3 made between January 11, 2019 and January 25, 2022. The recall was motivated by some slight differences found in the power semiconductors of rear motor inverters, according to Tesla’s statement.
In some cases, the inverters could not function normally to control electric current. When the hitch occurred in a static car, the car could not be started. When that happened to a running car, the car lost power, increasing the risk of a crash. Tesla said it will fix the problem through over-the-air (OTA) software update or send service personnel to do the software update for cars that cannot use OTA.