Fuel Level Sensor (FLS)
The Fuel Level Sensor (FLS) measures the fuel level in the fuel tank and uses its information to calculate the fuel evaporative pressure inside the fuel system. The fuel evaporative pressure is a critical element to determine proper operation of the EVAP system as the pressure changes according to the fuel levels. If the fuel level inside the fuel tank is either too high or too low, it is difficult to get a reliable fuel evaporative pressure value. The engine Electronic Control Unit (ECU) judges whether the fuel levels are within the qualifiable range by reading the output values of the FLS.