Software Bug Stalls Prius Hybrid Cars

Toyota plans to notify buyers of its Prius hybrid that the car could potentially stall out while driving due to a software bug in the Electronic Control Module (ECM). The problem affects approximately 75,000 cars, although only 33 official complaints have been lodged thus far.

Due to the bug, the Prius' gasoline engine could stall out while driving between 35 and 65 miles per hour. However, the car's electric engine would take over, enabling a driver to safely reach the side of the road. Upon stopping, the gasoline engine would properly restart, Toyota says.

Aside from the complaints made to the National Highway Traffic Safety Administration, Toyota has connected about 416 incidents to the software error and decided to contact customers about the defect. No injuries or accidents have been attributed to the bug, the company says.

Customers will receive a notice later this month instructing them to take their Prius to a dealer for the free software upgrade that resolves the problem. Aside from the bug in the ECM, Toyota will also fix a mechanical problem that can lead to stalling as well.

"This remedy should address most of the incidents," Toyota said on its Web site.

The Prius has become a hot seller this past year as gasoline prices continue to soar. September sales were up 90 percent from 2004, and Toyota expects to sell upwards of 200,000 Prius hybrids next year alone. With its gas and electric engine working in unison, the Prius can average close to 50 miles per gallon and never needs a charge.