The emergency flashers are used to warn other drivers when the vehicle has to be stopped in the road due to a breakdown, etc.
Press the switch.
All the turn signal lights will flash.
To turn them off, press the switch once again.

Emergency flashers
If the emergency flashers are used for a long time while the engine is not operating, the battery may discharge.
If your vehicle has to be
stopped in an
emergencyOn-vehicle inspection
NOTICE:
In this section, the terms "cold" and "hot" refer to the temperature of the
coils. "Cold"means approximately
-10 C (14 F) to 50 C (122 F). "Hot" means approximately 50 C (122 F) to 100 C
(212 F).
1. INSPECT IGNITION COIL ASSY (WITH IGNITER) AND PERFORM SPARK TEST
(a) Check for DTCs.
...