Car alarms typically go off for about 30 seconds to a few minutes before automatically shutting off. Most standard car alarms sound for around 30 seconds, but some can last up to 5 or even 10 minutes depending on the system
. There are differences based on the type of alarm system:
- Aftermarket alarms (installed after purchase) can sound for 5-10 minutes and tend to be more sensitive
- OEM (factory-installed) alarms usually go off for about 5 minutes and can be disarmed with the key fob
If a car alarm malfunctions or is faulty, it may continue sounding for much longer, sometimes up to 20 minutes or more, which can cause noise complaints and intervention by authorities
. In rare cases, especially with older or broken systems, alarms may sound until the car battery dies, which could take several hours
. In many cities, laws or ordinances require alarms to automatically shut off after a set time (often 5-10 minutes) to prevent noise disturbances. If an alarm goes off longer than this, police may be called, or the vehicle may be towed
Summary
- Typical duration: 30 seconds to a few minutes (usually up to 5-10 minutes)
- Aftermarket alarms: 5-10 minutes
- OEM alarms: about 5 minutes
- Faulty alarms: can last 20 minutes or more, sometimes until battery dies
- Local laws often limit alarm duration to prevent noise nuisance
To silence a car alarm, owners usually use the key fob or the car key to disarm it
