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Navi.zoneWhat is a fuel level sensor for GPS tracking
A fuel level sensor (often called DUT in Ukraine) is a probe installed in the fuel tank so you can see the level in litres, refuels and drains in the monitoring system. It works together with a GPS tracker: the sensor measures the level, and the tracker sends the data to the platform. If you're looking for a replacement factory sensor for a car, that's a different part — this is about fuel control for fleets and machinery.
How a fuel level sensor works
The probe is installed vertically in the tank, covering almost its full height. When the fuel level changes, the sensor registers it and continuously sends the value to the tracker.
The tracker receives the reading via a digital interface (RS232 or RS485) or an analogue input and sends it to the platform along with coordinates. So a fuel level sensor needs a tracker model with these inputs — for example, Teltonika FMB125.
On the platform, the level is converted to litres and a tank chart is built. The system marks a sharp rise as a refuel and a sharp drop as a drain, and sends an alert.
Because the level is sent continuously along with coordinates, the report shows not only how much fuel was in the tank but also where and when the level changed: while parked, at a filling station or on the move.
When you need a fuel level sensor
A fuel level sensor makes sense where the tank is large and fuel consumption is hard to check by eye: trucks, buses, agricultural and heavy machinery, generators. For a car or van, GPS tracking of routes and mileage or OBD data is often enough.
If the machine sends level and consumption via CAN, you can start with CAN. But when drains need to be recorded in litres, trucks are fitted with a fuel level sensor.
Why tank calibration matters
A tank is rarely a regular shape: narrowing sections, baffles, slopes. So the same change in level in different parts of the tank means a different number of litres.
Calibration means filling the tank in portions of known volume and recording the sensor reading at each step. The result is a “level → litres” table that is uploaded to the platform. Without calibration the chart shows the level but not exact litres. Each tank is calibrated separately: if a vehicle has two tanks, each needs its own sensor and calibration.
- fuel level in litres on a chart for any period;
- refuels: time, place and volume;
- drains and alerts about them;
- fuel consumption per trip, shift or month.
Fuel sensor, CAN or OBD: how to get fuel level data
There are three ways to get fuel data through a tracker. The choice depends on the vehicle and on what exactly you need to control.
- Fuel level sensor — a separate sensor in the tank. Suits trucks, buses, generators and anywhere catching drains matters.
- CAN — data from the vehicle's on-board bus: consumption, level and engine hours, if the specific model transmits them. No tank modification; the Teltonika FMB140 tracker reads CAN natively.
- OBD — reading via the diagnostic port of cars and vans (e.g. Teltonika FMB003). The simplest connection, but the data set depends on the vehicle.
Which platform you need for fuel control with a fuel level sensor
Fuel sensor data is processed by Wialon and Navi.zone on the Business plan, CAN data by Wialon: tank chart, refuel and drain reports, alerts. Wialon — from 195 UAH/mo per unit.
Navi.zone (from 37 UAH/mo) shows routes, mileage and areas on Base and Pro, and refuels and drains from a fuel sensor on the Business plan. CAN data is processed in Wialon.
Ready fuel control kit: Teltonika FMB125 tracker, fuel level sensor, installation and tank calibration — 9,839 UAH. Without installation — 6,050 UAH.
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