When the Engine Start/Stop button is in the ACC or ON position, if any door is open, the system checks for the smart key. If the smart key is not in the vehicle, the indicator will blink, and if all doors are closed, the chime will also sound for about 5 seconds. The indicator will go off while the vehicle is moving. Keep the smart key in the vehicle.
Hyundai Tucson (LM) 2010-2015 Service Manual: Smart Parking Assist System Sensor Repair procedures
Removal
Front SPAS sensor
1.
Remove the front bumper.
(Refer to the BD group - "Front bumper")
2.
Pull out the SPAS sensor (A) by opening the sensor holder out.
3.
Disconnect the connector form the sensor.
Rear SPAS sensor
1.
Lift the vehicle up by using Remove the front bumper.
...
Hyundai Tucson (LM) 2010-2015 Service Manual: Components and Components Location
Component Location
1. Rear glass defogger relay2. Rear glass defogger switch3. Rear glass defogger
...