If the light bulb does not operate, have the vehicle checked by an authorized HYUNDAI dealer.
Hyundai Elantra AD (2016-2020) Service Manual: Blind Spot Detection Indicator Repair procedures
Removal
Blind Spot Detection Warnig Indicator
1.
Disconnect the negative (-) battery terminal.
2.
Remove the mirror (A).
Installation
Blind Spot Detection Warnig Indicator
1.
Install the outside mirror.
2.
Connect the negative (-) battery terminal.
Inspection
1.
Apply battery ...
Hyundai Elantra AD (2016-2020) Service Manual: Canister Repair procedures
Removal
1.
Turn the ignition switch OFF and disconnect the battery negative (-) cable.
2.
Lift the vehicle.
3.
Disconnect the ventilation hose (A), and canister close valve extension connector (B).
4.
Disconnect the vapor tube quick-connector (A).
5.
Remove installation nuts ...