Module, Vehicle Tracking: Operation: Operation

In normal operation, the Body Control Module (BCM) will request from Vehicle Tracking Module (VTM) a code status request, using the CAN B network each time the ignition is cycled from off to on. The VTM at each request will send a code status response using the CAN B network back to the BCM. If the the vehicle is stolen the owner contacts the Service Provider and requests that the vehicle be Blocked. The Service Provider sends a Blocking command to the VTM. The VTM stores the Block command in memory. The next time the ignition is cycled from off to on, the BCM requests a code status from the VTM. The VTM will respond with a Block status message back to BCM and the engine will not start. In addition to preventing the vehicle from starting, the VTM will also send a GPS signal back to the Service Provider with it current position. If the battery is disconnected the VTM has an internal back up battery to power the module for several hours.

Once the vehicle is recovered, the owner contacts the Service Provider and requests that the vehicle be Unblocked. The Service Provider sends an Unblocking command to the VTM. The VTM stores the Unblock command in memory. The next time the ignition is cycled from off to on, the BCM requests a code status from the VTM. The VTM will respond with an Unblock status message back to BCM and the engine will be allowed to start.