When electronic warfare is active, a tracker loses satellites or receives false coordinates, and the mileage in reports drifts. Here is why, and how to take mileage from the vehicle odometer via CAN.
A standard GPS tracker calculates mileage from coordinates: it joins the track points and adds up the distances between them. When satellites are clearly visible, the error is small. During air raid alerts, electronic warfare is active across Ukraine, and the GPS signal is jammed or spoofed.
What happens to the track during jamming
- Jamming. The tracker cannot see satellites and stops recording coordinates. The report shows a straight line across the city, and part of the mileage simply disappears.
- Spoofing. The tracker receives a false position: the vehicle jumps kilometres away on the map and back. Each jump adds mileage that never happened.
That is why report mileage stops matching the odometer, and you cannot use it for fuel, allowances or maintenance.
Where to get accurate mileage
A modern vehicle counts its own mileage: that is the odometer on the dashboard. This data travels over the CAN bus. A CAN tracker such as the Teltonika FMB140 reads it directly, so report mileage matches the dashboard even when GPS is down. Fuel level, consumption and engine RPM are usually available from CAN too. The data depends on the make, model and year, so we check the vehicle by VIN before installation.
Who needs it most
- Distribution and delivery. Vans run city routes every day, and fuel is one of the largest costs.
- Sales reps in their own cars. Fuel and wear allowances are calculated from business mileage. An OBD tracker plugs into the port with no installation; you need the rep’s written consent.
- Chief mechanic. Maintenance by actual mileage and, if the vehicle sends fault codes over OBD or CAN, an alert before the vehicle breaks down.
What it costs
A Teltonika FMB140 tracker with CAN and installation is 6,349 UAH per vehicle, and Wialon is 195 UAH a month per vehicle. A standard FMB920 GPS tracker with installation is 2,600 UAH: it shows the route, but mileage during jamming will be inaccurate.
You can estimate what unaccounted mileage costs your fleet on the GPS for distribution page.
