Indicator Light

When the ignition switch is in the ON position, the ESC indicator illuminates, then turns off if the ESC system is operating normally.
The ESC indicator flashes when the ESC system is operating.
If the ESC indicator remains illuminated, there may be a malfunction in the ESC system. When this warning light illuminates, have your vehicle checked by an authorized HYUNDAI dealer as soon as possible.
The ESC OFF indicator illuminates when the ESC system is turned off.
WARNING
When the ESC indicator flashes, it means ESC is active:
Drive slowly and NEVER attempt to accelerate. NEVER turn off ESC while the ESC indicator is flashing, or you may lose control of the vehicle, which may result in an accident.
NOTICE
Driving with wheels and tires of 5 different sizes may cause the ESC system to malfunction. Before replacing tires, make sure all four tires and wheels are the same size. Never drive the vehicle with wheels and tires of different sizes installed.
Test yourself
A quick Hyundai Elantra AD quiz: every answer comes with an explanation and a link to the manual page.