2002 Toyota Prius Owners Manual - Page 108

(c) Hybrid System Warning Light ( ) This light comes on if there is a problem in the electric motor, inverter unit, hybrid vehicle battery, etc. If this light is on, stop your vehicle in a safe place immediately and contact your Toyota dealer. Even if the hybrid system warning light comes on, you could increase the speed a little temporarily by depressing the accelerator pedal. Immediately pull up your vehicle at a safe place and contact your Toyota dealer. 99