Fuel Level Sensors

Courtesy of JAGUAR CARS, INC.

Two identical fuel level sensors are installed in the fuel tank. One is mounted on the pump module and one is mounted on the remote pump housing. The fuel level sensors are connected to the battery junction box (BJB) via the connector on the mounting flange.

The fuel level sensors are magnetic passive position sensors. Each sensor consists of a sealed housing that contains 51 film resistors mounted in an arc on a ceramic surface. The film resistors range in value from 51.2 to 992.11 Ohms and are wired in series with individual contacts. A soft magnetic foil with 51 flexible contacts is mounted a small distance above the film resistors. A magnet, located below the ceramic surface, is attached to a lever and float arm.

The magnet pulls the flexible contacts onto the opposing film resistor contacts, forming an electrical circuit. As the float arm moves, the magnet follows the arc of film resistors and changes the point at which the flexible contacts are pulled onto the opposing film resistor contacts, which changes the resistance in the circuit.

Sensor Operating Principle 

Courtesy of JAGUAR CARS, INC.