Toyota to fix 650,000 Prius hybrids over heat
The repair campaign covers Prius cars for the model years 2004 to 2007. The bulk of the cars, or 378,000 units, are in the United States.
The Japanese automaker said it had not received any reports of accidents or injuries from problems with the pump, which circulates coolant for the hybrid system
Major automakers, including Toyota, often conduct repair campaigns that are separate from safety recalls filed with U.S. regulators in cases where they determine that a defect does not present a safety risk.
Toyota said the design of the electric water pump let air bubbles enter the system, slowing coolant circulation and allowing the hybrid's components to heat up.
The heating up of the components could trigger a warning light. If left unattended, the Prius could overheat and drop into a "fail-safe" mode where engine power would be reduced, Toyota said.
Toyota said it would begin notifying owners of the Prius repair campaign in the United States in early December.