Fuel Level Sensor
| ITEM | DESCRIPTION |
|---|---|
| 1 | Fuel level sensor - 'A'/'B' |
| 2 | Fuel level sensor float arm |
| 3 | Fuel level sensor float |
Two fuel level sensors are installed in either side of the saddle tank. The sensors are a float operated MAgnetic Passive Position Sensor (MAPPS) which provide a variable resistance to ground for the output from the fuel gauge. The sensor is sealed from the fuel preventing contamination of the contacts, increasing reliability. The fuel level sensors are connected to the external electrical connector on the flange via the connector on the underside of the fuel pump module flange.
The sensor comprises a series of film resistors mounted in an arc on a ceramic surface. The resistors are wired in series with individual contacts. A soft magnetic foil with flexible contacts is mounted a small distance above the film resistors. A magnet, located below the ceramic surface, is attached to the sender unit float arm. As the float arm moves, the magnet follows the same arc as the film resistors. The magnet pulls the flexible contacts onto the opposite film resistor contacts forming an electrical circuit.
| ITEM | DESCRIPTION |
|---|---|
| 1 | Magnetic foil |
| 2 | Spacer |
| 3 | Ceramic surface |
| 4 | Magnet |
| 5 | Resistance film |
The film resistors are arranged in a linear arc with resistance ranging from 51.2 to 992.11 Ohms. The electrical output signal is proportional to the amount of fuel in the tank and the position of the float arm. The measured resistance is processed by the Instrument Cluster (IC) to implement an anti-slosh function. This monitors the signal and updates the fuel gauge pointer position at regular intervals, preventing constant pointer movement caused by fuel movement in the tank due to cornering or braking.
A warning lamp is incorporated in the IC and illuminates when the fuel level is low.