Fuel Level Sending Unit / Sensor: Operation

As the fuel level increases, the float and arm move up. This decreases the sending unit resistance, causing the fuel gauge on the instrument panel to read full. The fuel level sensor (fuel gauge sending unit) sends a signal to the BCM. The BCM sends the signal over the PCI bus circuit to the PCM to indicate fuel level. The purpose of this feature is to prevent a false setting of misfire and fuel system monitor trouble codes if the fuel level is less than approximately 15 percent of its rated capacity. It is also used to send a signal for fuel gauge operation via the PCI bus circuits.