2010 Toyota Avalon Owners Manual - Page 440

5-2. Steps to take in an emergency STEP 3 To change the "ENGINE START STOP" switch modes: Within 5 seconds of the buzzer sounding, release the brake pedal and press the "ENGINE START STOP" switch. Modes can be changed each time the switch is pressed. (→P. 133) To start the engine: Press the "ENGINE START STOP" switch within 5 seconds after the buzzer sounds, keeping the brake pedal depressed. If the "ENGINE START STOP" switch still cannot be operated, contact your Toyota dealer.