Vehicles can be remotely immobilized by sending a command to the tracker. If the tracker supports GPRS commands, then you can issue a GPRS command from the vehicle tracking platform to effect immobilization.
Some trackers do not support GPRS commands. Immobilization can be done with these trackers by sending SMS commands to the tracker.
When the tracker receives a command to immobilize, an open collector output of the device is enabled which will activate a relay which will, in turn, open the power going to the starter motor. Without the power reaching the starter motor, you won’t be able to start the vehicle. This is the principle of immobilization.
Immobilization can also be effected in conjunction with an iButton. Trackers can be configured to turn off the output when an iButton is tapped on its reader. This will, in turn, deactivate a relay. The relay when deactivated will close the power going to the starter motor. The vehicle can then be started.
The unique ID of the iButton can be stored in the tracker and the tracker can be configured to check the ID when an iButton is tapped on the connected reader. If the ID of the tapped iButton matches an entry in the stored list of unique IDs, the relay is de-energized. This will, in turn, close the power going to the starter motor. The vehicle can then be started. In this case, which is termed as an authorized driving scenario, only those drivers with iButtons whose unique IDs are pre-approved and stored in the tracker will be able to start the vehicle. This prevents unauthorized use of vehicle and theft.