Patent ID: 7808371

Claim:
A vehicle security unit for installation inside a vehicle of a fleet of vehicles and in wireless communication with a master unit, said vehicle being associated with a vehicle identification code, the vehicle security unit comprising: an armed mode to be active or inactive; a disturbance event detection system for detecting a disturbance event and a type of disturbance associated with said vehicle; a security key reader for reading a security key, and for producing a security key reading event in response to the reading, said security key having a key identification code; a vehicle transmitter for transmitting a disturbance event message comprising said type of disturbance to said master unit in response to said disturbance event if said security mode is active and for transmitting a security key reading event message to said master unit in response to said security key reading event, said disturbance event message and said security key event message comprising said vehicle identification code and said security key event message comprising said key identification code; a receiver for receiving a command from said master unit to deactivate said armed mode; and an on-board diagnostic connector and a battery wherein said vehicle security unit has an on-board diagnostic input to be connected to said on-board diagnostic connector for detecting at least a voltage drop event in said battery, said disturbance event comprising said voltage drop event.