If your vehicle is showing car alarm goes off randomly for no reason, here are the most likely causes and the parts you'll need to fix each one.
A dying battery causes voltage fluctuations that the alarm system interprets as someone trying to tamper with the vehicle's power supply or disconnect the battery.
The sensor that detects if the hood is closed is often built into the hood latch mechanism. If it gets dirty, corroded, or fails, it falsely triggers the alarm by making the car think the hood is being forced open.
These components tell the car's computer when a door is opened or locked. A failing switch or actuator can send a false 'door open' signal while the car is armed, instantly triggering the alarm.
A damaged key fob might have a stuck panic button, or a dying fob battery can sometimes send erratic signals to the car's receiver.
If an aftermarket alarm was recently installed, poor wiring connections or a shock sensor set too high can cause false triggers from wind, passing trucks, or temperature changes.
The BCM controls the vehicle's electronics, including the security system. Water intrusion or internal electrical failure can cause erratic alarm behavior and other strange electrical gremlins.