2008 Toyota Prius Owners Manual - Page 458

5-2. Steps to take in an emergency Alarm Exterior alarm: One beep (sounds for 2 seconds) Warning light Details The lock button has been pressed while the hybrid system is not OFF and the shift position is in "P". The vehicle's ID code detection system has judged that the smart key is not present when the "POWER" switch is pressed. Correction procedure Turn the hybrid system OFF. Interior alarm: One beep (for 5 seconds) Check that the smart key is in the vehicle and within the detection area. 432 PRIUS_U_(L/O_0802)