How to Activate a Car Alarm

by Shanan Miller
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There are two types of alarms available for a car. Drivers can purchase a passive or active alarm system. A passive alarm system requires user interaction to activate, while an active alarm does not. The active alarm initiates automatically, usually several minutes after the ignition is turned off or after the car door has been opened and closed. Otherwise, you can use your key fob to set the alarm, which also locks and unlocks your doors.

Step 1

Get your key fob and locate the lock button. The lock button might read "Lock" in small print or it may include a picture of a lock in its locked position.

Step 2

Press the lock button once. Press it quickly and use pressure. Do not hold it down.

Listen for a beeping sound. Some vehicles activate the alarm after one press of the button. If it does not beep, you'll hear all of the doors lock. Press the lock button again to activate the alarm.


  • If you cannot activate your alarm with the key fob because it has a dead battery, try to open the driver's-side door and hit the power "Lock" button, usually located by the door handle or power-window buttons. Hit the button twice and close the driver's side door.
  • All doors and trunk or hatch must be completely closed for the alarm to activate.
  • Additional information about your alarm system is located in your owner's manual.


  • Issues with an active alarm system require the help of a professional. Call a dealership for servicing if you suspect that you might have a problem with the vehicle's electrical system.

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