2004 Toyota Prius Owners Manual - Page 221

Brake system REGENERATIVE BRAKE When the brake is applied, the electric motor used as a generator converts kinetic energy into electric energy. The regenerative brake works in the following operations. 1. When the accelerator pedal is leased, the reduced speed equal to gine braking in a gasoline−fueled hicle is obtained in accordance with running mode position of the shift ver. reenvethe leHYDRAULIC BRAKE This brake system has 3 independent hydraulic circuits. If either circuit should fail, the other will still work. However, the pedal will be harder to press, and your stopping distance will increase. Also, the brake system warning light may come on. The yellow brake system warning light may stay on for about 60 seconds after the "IG−ON" mode is enabled. It is normal if the light turns off after a while. Depressing the brake pedal repeatedly may turn on the red brake system warning light and buzzer. It is normal if the light turns off and the buzzer stops sounding after a few seconds. You may hear a small sound in the engine compartment after the hybrid system is started or the brake pedal is depressed repeatedly. This is a pump pulsating sound of the brake system, and it is not a malfunction. In the following conditions, you may hear a motor sound in the engine compartment. CAUTION Do not drive your vehicle with only a single brake system. Have your brakes fixed immediately. BRAKE ACTUATOR The brake actuator uses brake fluid pressurized by the pump to power−assist the brakes. If the brake actuator fails during driving, the brake system warning light comes on and buzzer sounds continuously. In this case, the brakes may not work properly. If they do not work well, depress the brake pedal firmly. If the brake system warning light comes on, immediately stop your vehicle and contact your Toyota dealer. 2. When the brake pedal is depressed with the shift lever in "D" or "B", the regenerative brake works. D The brake pedal is depressed when the hybrid system is turned off. D The driver's door is opened. D For a few seconds after the hybrid system is "OFF" and about 90 seconds have passed. The brake pedal stroke may be short when you press the "POWER" switch with the brake pedal depressed. 209