Car alarm

History and Evolution of Car Alarms
– Car alarm invented in 1913 as a theft deterrent
– Early version triggered when someone tried to crank the engine
– Later version had a receiver that buzzed if the ignition system was tampered with
– Remote starter alarm published in 1916
– Manual arming and triggering of early car alarms

Features of Car Alarms
– Car alarms are different from immobilizers
– Immobilizers do not offer audible or visual deterrence
– Car alarms can be OEM or aftermarket
– Remote car alarms have additional radio receivers
– Keyless remote car alarms use strong cryptography authentication methods

Arming and Disarming of Car Alarms
– Car alarms are typically armed and disarmed by remotes
– OEM alarms can be armed and disarmed with the keyless entry remote
– Power door lock switch can arm or disarm some vehicles
– Ignition turning on can disarm the system in some cases
– Aftermarket alarms are armed and disarmed via remote, with an override switch

Triggers of Car Alarms
– OEM alarms monitor doors, trunk/hatch, hood, and ignition
– Aftermarket alarms have shock sensors and two-wire connections
– More sophisticated aftermarket alarms are wired into the vehicle’s electronics
– Optional sensors include tilt, sound discriminator, proximity, and motion sensors
– False triggers can occur due to loud noises or passerby movements

Effectiveness and Controversies of Car Alarms
– Car alarms installed in the 1980s and 1990s are easily triggered accidentally
– High sensitivity settings often lead to ignored alarms
New York City Police Department claimed car alarms may increase theft and break-in crimes
– Thieves may use car alarm sounds to conceal breaking windows
– Many vehicle manufacturers no longer prioritize car alarms due to false alarmsSources: