The Technical Definition: The vehicle's security system has detected a fault or a depleted internal backup battery within the alarm siren module itself.

Common Symptoms: The vehicle's security alarm may trigger randomly without cause, the siren may sound extremely faint or muffled, or a general "Vehicle Security" error may log in the computer.

Typical Fix: The internal backup battery inside the siren unit is sealed (potted) to protect it from the elements and cannot be replaced independently. The standard repair is unbolting the old siren module and plugging in a complete replacement unit.