What is the reason for BYD's alarm to keep ringing?
4 Answers
BYD's alarm keeps ringing due to a faulty door contact switch, which can also cause the alarm to sound. It is necessary to go to a repair shop for maintenance. The sensitivity of the anti-theft sensor is too high. There is a sensitivity adjustment knob on the anti-theft vibration sensor, which can be fine-tuned. Alarm working principle: When the sensor is struck or shaken, the ball inside the chamber will roll. When it rolls away from a smaller secondary electrical contact element, the circuit formed by this secondary electrical contact element and the central electrical contact element will be disconnected. Controller ball displacement: At this time, the switch will open, indicating that the controller ball has been displaced. As the ball continues to roll past other secondary electrical contact elements, the circuit will repeatedly close and open until the ball finally stops rolling.
It can be quite annoying when the alarm on your BYD suddenly goes off incessantly. I've encountered this situation several times. The most common cause is when the doors or trunk aren't closed properly, making the system think someone is breaking in. Last time this happened to me at a gas station, it turned out the trunk wasn't fully closed because it was overloaded with luggage. Other situations like accidental key fob presses or dead remote battery can also trigger false alarms. Also pay attention to the sensitivity of the vibration sensor - sometimes even vibrations from passing trucks can set it off. If the battery voltage is unstable or aftermarket electrical equipment isn't properly wired, it can also disrupt the alarm system. If you can't find the cause, you might try disconnecting the negative battery terminal for half a minute and reconnecting it, which essentially reboots the system. Just remember to reset the one-touch window function afterward.
Last month, my neighbor Lao Wang's BYD F3 had the same issue—it went off in the middle of the night, waking up the entire building. It turned out the hood trigger switch was stuck and hadn't reset; a few gentle presses fixed it. Nowadays, new energy vehicles are even more delicate. Issues like water getting into the rain sensor on the windshield or improperly installed dashcam power connections can easily trigger false alarms. Especially for cars with modified circuits, extra caution is needed. I’d suggest first checking the latch status of all four doors, then seeing if the central display shows any warning icons. Once, while removing a door panel, I accidentally loosened the wiring for the ultrasonic sensor, causing the car to randomly alarm when parked—reconnecting the plug tightly solved it. If all else fails, a trip to the 4S shop to scan for trouble codes with their diagnostic computer is the most reliable solution.
BYD car alarms going off continuously are mostly false triggers. Key areas to inspect fall into five categories: aging door contact switches are the most common, especially the sensor near the driver's door handle; unstable battery voltage can disrupt the entire electronic system; the lock button on the remote key might be stuck or the battery drained; the trunk's closure sensor could be obstructed by debris; or the vehicle tilt sensor might be falsely activated on bumpy roads. Last time, a colleague's car alarm blared for twenty minutes in a mall parking garage—turned out a stray cat under the car had triggered the ultrasonic sensor. Another easily overlooked culprit is the hood latch sensor, which is particularly prone to false alarms during rainy weather. A quick fix is to press and hold the unlock button on the key fob to forcibly deactivate the alarm.
