Why is it the door beeps when the car is running on a 97 Honda Civic EX?

The beeping sound in a 1997 Honda Civic EX when the door is open while the engine is running serves as a warning alert. It reminds the driver that the door is ajar, which could pose a safety risk while driving. This feature helps prevent accidental door openings while the vehicle is in motion and alerts the driver to secure the door before driving. Additionally, it can indicate that the key is still in the ignition when the door is open.