How to check auto smart key is working or not

To check smart key is working or not just go near the vehicle and try to open the door by pulling the door handle if vehicle door do not open then unlock the door first with key fob unlock button, if door do not open with key fob the put out the key and from key fob and open the door with machinal key
and get inside the vehicle sit on driver seat and press the brake padal and look as you press the brake padal and see push button light illuminate or not

How to check smart key is working or not

 if do not illuminate then change the key fob battery.

if after changing the fob's cell you are getting problem then take vehicle to near dealership.