One problem related to tail light switch has been reported for the 2010 Toyota Prius. The most recently reported issues are listed below.
Vehicle's brake lamp bulbs stopped working (headlamps on/off no change except the upper bulb on the rear lights are illuminated w/headlamps/high beams on as they should be while the rest of the light is indifferent to brake pedal application, changing from park/drive etc). The bulbs were replaced but the issue persists, suspect it is something to do with the wiring harness. Please remedy because any electrical diagnostic is hundreds of dollars at the dealership and may not even be obligatory if a known issue & cost effective solution exist. Regardless of cost Toyota should offer any remedy that protects the safety of their consumers. I just don't want to have to pay a bunch of money to determine the problem was a loose screw. Anyway, faulty brake/tail lights increase the possibility of collision & endanger other drivers when a defect of this nature presents itself. Both right & left are affected, there is no visible warning the vehicle is slowing rather than driving, stopped, idling, or accelerating.