Always set the parking brake before leaving the vehicle. To apply the parking brake:
Firmly depress the brake pedal.
Pull up the parking brake lever as far as possible.
WARNING
To reduce the risk of SERIOUS INJURY or DEATH, do not operate the parking brake while the vehicle is moving except in an emergency situation. It could damage the brake system and lead to an accident.
To release:
Firmly depress the brake pedal. While pressing the release button (1), slightly pull up on the parking brake lever then lower the parking brake lever (2).
If the parking brake does not release or does not release all the way, have your vehicle checked by an authorized HYUNDAI dealer.
WARNING
NOTICE
Check the Parking Brake Warning Light by placing the ignition switch to the ON position (do not start the engine).
This light will be illuminated when the parking brake is applied with the ignition switch in the START or ON position. Before driving, be sure the parking brake is released and the Brake Warning Light is OFF.
If the Parking Brake Warning Light remains on after the parking brake is released while engine is running, there may be a malfunction in the brake system. Immediate attention is necessary.
If at all possible, cease driving the vehicle immediately. If that is not possible, use extreme caution while operating the vehicle and only continue to drive the vehicle until you can reach a safe location.
Hyundai Elantra AD (2016-2020) Owners Manual: Drive Mode Integrated Control System
The drive mode may be selected according to the driver's preference or road condition.
Information
If there is a problem with the instrument cluster, the drive mode will be
in NORMAL mode and may not change to SPORT mode.
The mode changes, as below, whenever the DRIVE MODE button is press ...
Hyundai Elantra AD (2016-2020) Service Manual: Parking Brake Switch Repair procedures
Removal
1.
Disconnect the negative (-) battery cable.
2.
Release the parking brake.
3.
Remove the floor console assembly.
(Refer to Body - "Floor console")
4.
Disconnect the connector (A) of parking brake switch.
5.
Loosen the screw and then remove the parking brake switch.
...