Toyota announced a voluntary safety recall on the 2010 Prius and 2010 HS 250h to update software in the vehicle's anti-lock brake system. Toyota also recalled them in Europe and Japan, adding in the Sai Hybrid in Japan.
First and second generation Prius are not affected by this recall (but you may want to read this article about that).
That affects 133,000 Prius and 14,550 Lexus HS in the US, and around 400,000 vehicles worldwide.
Toyota has already implemented the software fix on their production lines, so only Prius produced after May 2009 are affected. The HS 250h will have its production line changed later this month.
According to the statement from Toyota:
The ABS, in normal operation, engages and disengages rapidly (many times per second) as the control system senses and reacts to tire slippage. Some 2010 Model Year Prius and 2010 HS 250h owners have reported experiencing inconsistent brake feel during slow and steady application of brakes on rough or slick road surfaces when the ABS is activated in an effort to maintain tire traction.The HS 250h and Toyota Sai are built on the Prius platform, so the same issue affects all three vehicles.
Toyota has responded to owner concerns with a running production change for 2010 Prius that was introduced last month, improving the ABS response time, as well as the system's overall sensitivity to tire slippage.
Toyota will begin mailing letter to Prius owners next week, while HS 250h owners will be notified in a few weeks.
Detailed information about these recalls is available to customers at www.toyota.com/recall and at the Toyota Customer Experience Center at 1-800-331-4331, or the Lexus Customer Assistance Center at 1-800-255-3987.