Upon initial boot-up, a telematics device receives a PID map in response to a PID map request. The TCU may send multiple PID map requests for different mode and PID combinations over a vehicles communication bus, and then may append each received PID map to the already-received PID maps. The multiple PID maps appended to one another form a composite bit value, or composite PID map. The composite PID map is processed according to a hash algorithm, resulting in a pseudo-VIN. Upon subsequent boot-ups of the TCU, the TCU sends the multiple PID map requests over the vehicle's bus and generates a pseudo VIN following the same steps as it did at initial boot-up. The TCU compares the currently generated pseudo-VIN to the initial pseudo VIN; if it determines a mismatch, it sends a notification to an interested third party that indicates improper usage of the TCU.