One problem related to lose power steering has been reported for the 2002 Toyota Prius. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2002 Toyota Prius based on all problems reported for the 2002 Prius.
The electronic power steering assembly malfunctions and stops providing assistance to the driver on a 2002 Toyota Prius, on one instance the gasoline motor stopped working and I was left driving at low speed with the assistance of the electric motor only. The latest incident occurred on may 31st, 2010 while driving at about 65 mph on a freeway, the car lost the power steering operation, multiple warning lights came on the screen, the gas motor shut down and the speed of the car dropped to around 23 mph. The accelerator pedal was responsive only in the range of 0~23 mph. I took the car to a service center and the service advisor told me the electric power steering module was defective and needed replacement. Reviewing the service records for the cars I found that it presented the same symptoms once in 2006 and three times in 2008. The service center either cleaned a sensor or couldn't replicate the problem. The part was never replaced. While researching NHTSA site I found that Toyota has file tsbs back in 2004 recognizing a problem with this particular component and in some cases extended the warranty on the part. I contacted Toyota and they refuse to assist in the cost of the car repair.