This system helps to protect your vehicle and valuables. The horn will sound and the hazard warning lights will blink continuously if any of the following occur:
- A door is opened without using the remote key or smart key.
- The trunk is opened without using the remote key or smart key.
- The engine hood is opened.
The alarm continues for 30 seconds, then the system resets. To turn off the alarm, unlock the doors with the remote key or smart key.
The Theft Alarm System automatically sets 30 seconds after you lock the doors and the trunk. For the system to activate, you must lock the doors and the trunk from outside the vehicle with the remote key or smart key or by pressing the button on the outside of the door handles with the smart key in your possession.
The hazard warning lights will blink and the chime will sound once to indicate the system is armed.
Once the security system is set, opening any door, the trunk, or the hood without using the remote key or smart key will cause the alarm to activate.
The Theft Alarm System will not set if the hood, the trunk, or any door is not fully closed. If the system will not set, check the hood, the trunk, or the doors are fully closed.
Do not attempt to alter this system or add other devices to it.
Information
 Safe Exit Assist (SEA) System
Safe Exit Assist (SEA) System Driver Position Memory System
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   Brake Booster Operating Test 
For simple checking of the brake booster operation, carry out the following tests.
1.
Run the engine for one or two minutes, and then stop it. If 
the pedal depresses fully the first time but gradually becomes higher 
when depressed succeeding times, the booster  ...
   
Hyundai Elantra AD (2016-2020) Service Manual: Components and Components Location
   Component Location
1. DDM (Driver Door Module)2. ADM (Assist Door Module)3. SJB (Smart Junction Block)4. Door lock knob5. Trunk lid actuator6. Door latch module7. Door lock/unlock switch8. RLDM (Rear Left Door Module)9. RRDM (Rear Right Door Module)
 ...