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 needs to be towedVehicle Speed Sensor "A" Intermittent / Erratic / High (P0503)
DESCRIPTION
If a malfunction (a rapid change in vehicle speed) in the vehicle speed signal
being output from the skid control ECU is detected while the cruise control is in
operation, the ECM determines that there is a momentary interruption or noise, and ...
Precaution
PRECAUTION
1. PRECAUTION FOR DISCONNECTING CABLE FROM NEGATIVE BATTERY TERMINAL
NOTICE:
When disconnecting the cable from the negative (-) battery terminal, initialize
the following systems after the terminal is reconnected.
System Name
...
Crankshaft Position Sensor "A" Circuit (P0335,P0339)
DESCRIPTION
The crankshaft position sensor system consists of a crank angle sensor plate
and a pickup coil.
The sensor plate has 34 teeth and is installed on the crankshaft. The pickup
coil is made of wound copper wire, an iron core and magnet. The senso ...