Toyota PRIUS ALPHA 2012 Quick Reference Manual page 531

5-2. Steps to take in an emergency
Warning message
(Flashes
3 times)
■
Approach warning message
In the following instances, there is the possibility that the approach warning
will not activate even when the vehicle-to-vehicle distance decreases.
●
When your vehicle and the vehicle ahead are traveling at the same
speed or the vehicle ahead is traveling more quickly than your vehicle.
●
When the vehicle ahead is traveling at very low speed.
●
Immediately after cruise control speed is set.
●
At the instant the accelerator pedal is depressed.
516
Details
EV drive mode has been auto-
matically canceled.
A buzzer also sounds.
The reason why EV drive
mode cannot be used is
shown on the second line
(may not be shown in some
instances.)
Correction
procedure
Drive normally for a
short time.