Fuel Sender Assembly
WARNING: This page is about a different car, the 2003 Pontiac Sunfire, 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, and 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
The fuel sender assembly consists of the following:
- Fuel Level Sensor - The fuel level sensor consists of a float, a wire float arm, and a ceramic resistor card. The position of the float arm indicates the fuel level. The fuel level sensor contains a variable resistor which changes resistance in correspondence with the position of the float arm. The Powertrain Control Module (PCM) sends the fuel level information via the Class 2 circuit to the Instrument Panel Cluster (IPC). This information is used for the IPC fuel gauge and the low fuel warning indicator, if applicable. The PCM also monitors the fuel level input for various diagnostics.
- Fuel Tank Pressure Sensor - The Fuel Tank Pressure (FTP) sensor measures the difference between the pressure or vacuum in the fuel tank and outside air pressure. The Powertrain Control Module (PCM) provides a 5-volt reference and a ground to the FTP sensor. The FTP sensor provides a signal voltage back to the control module that can vary between 0.1-4.9 volts. As FTP increases, FTP sensor voltage decreases, high pressure = low voltage. As FTP decreases, FTP voltage increases, low pressure or vacuum = high voltage.
- Fuel Pump - See FUEL PUMP under FUEL DELIVERY.
- Fuel Strainer - The fuel strainer attaches to the lower end of the fuel sender. The fuel strainer is made of woven plastic. The functions of the fuel strainer are to filter contaminants and to wick fuel. The fuel strainer normally requires no maintenance. Fuel stoppage at this point indicates that the fuel tank contains an abnormal amount of sediment or contamination.
- Fuel Filter - The fuel filter is located on the fuel feed pipe, between the fuel pump and the fuel injectors. The paper filter element traps particles in the fuel that may damage the fuel injection system. The filter housing is made to withstand maximum fuel system pressure, exposure to fuel additives, and changes in temperature.
- Fuel Feed and Return Pipes - The fuel feed pipe carries fuel from the fuel tank to the fuel injection system. The fuel return pipe carries fuel from the fuel injection system back to the fuel tank. The fuel pipes consist of the rear fuel pipe assemblies are located from the top of the fuel tank to the chassis fuel pipes. The rear fuel pipes are constructed of nylon. Also, chassis fuel pipes are located under the vehicle and connect the rear fuel pipes to the fuel injection system. The chassis fuel pipes are constructed of steel.