Circuit Description

The fuel level sensor is mounted in the fuel level sensor unit. The sensor detects a fuel level in the fuel tank and transmits a signal to the unified meter and A/C amp. The unified meter and A/C amp sends the fuel level sensor signal to the ECM through CAN communication line. It consists of 2 parts. One is a mechanical float. The other is a variable resistor. Fuel level sensor output voltage changes depending on movement of the fuel mechanical float.

When the vehicle is parked, naturally the fuel level in the fuel tank is stable. It means that output signal of the fuel level sensor does not change. If ECM senses sloshing signal from the sensor, fuel level sensor malfunction is detected.