Toyota has issued a recall for 2.4 million Prius and Auris hybrids worldwide. In the US, the recall covers approximately 807,000 examples of the 2010-2014 Prius and 2012-2014 Prius V. The vehicles in question, including those found in other countries, carry build dates between October 2008 and November 2014.
The issue stems from the vehicles' software. When a fault is discovered in the hybrid system, the cars in question should default to a "failsafe" driving mode (often referred to as "limp" mode) that will allow the vehicle enough power to get off the road and to a safe place. In the recalled vehicles, however, they might lose power and stall instead of going into "limp" mode, which could increase the risk of a crash if it happens at a bad time.
According to Toyota's release, this issue was also addressed in two prior recalls from 2014 and 2015. This new recall addresses a condition that the last two recalls "did not anticipate."
Thankfully, fixing the problem requires no hardware alterations. Dealership technicians will apply a software patch to the recalled vehicles, which should clean the problem up and ensure that "limp" mode activates when it should. Toyota will send recall notifications via first-class mail when the necessary software updates are available.