Hyundai Sonata: Cruise Control / Cruise Control will be canceled when

Hyundai Sonata LF 2014-2019 Owners Manual / Driving your vehicle / Cruise Control / Cruise Control will be canceled when

Depressing the brake pedal.
Pressing the CANCEL switch located on the steering wheel.
Pushing the CRUISE button. Both the CRUISE indicator and the SET indicator will turn OFF.
Moving the shift toggle switch into N (Neutral).
Decreasing the vehicle speed lower than the memory speed by 5 mph (10 km/h).
Decreasing the vehicle speed to less than approximately 20 mph (30 km/h).
The ESC (Electronic Stability Control) is operating.
Downshifting to the 2nd gear in Manual shift mode.

Information

Each of the above actions will cancel Cruise Control operation (the SET indicator light in the instrument cluster will go off), but only pressing the CRUISE button will turn the system off. If you wish to resume Cruise Control operation, push the toggle switch up (RES+) located on your steering wheel. You will return to your previously preset speed, unless the system was turned off using the CRUISE button.

To decrease Cruise Control speed

Push the toggle switch (1) down (SET-) and hold it. Your vehicle will gradually slow down. Release the toggle switch at the speed you want to maintain. Push the toggle switch (1) down (SET-) and ...

To resume preset Cruising speed

Push the toggle switch (1) up (RES+). If the vehicle speed is over 20 mph (30 km/h), the vehicle will resume the preset speed. ...

Other information:

Hyundai Sonata LF 2014-2019 Owners Manual: On curves
The Smart Cruise Control System may not detect a moving vehicle in your lane, and then your vehicle could accelerate to the set speed. Also, the vehicle speed will decrease when the vehicle ahead is recognized suddenly. Select the appropriate set speed on curves and apply the brakes or accel ...

Hyundai Sonata LF 2014-2019 Owners Manual: Radar to Detect Distance to the Vehicle Ahead
The Smart Cruise Control uses a radar to detect distance to the vehicle ahead. Radar check message If the radar or cover is dirty or obscured with foreign matter such as snow, this message will appear. In this case, the system may not function temporarily, but it does not indicate a malfunction ...