Q: How to check and replace the fuel level sending unit in a Nissan Quest?
A: Raise the vehicle and support it securely on jackstands. Disconnect the electrical connector at the rear of the Fuel Tank for the Fuel Pump/fuel level sensor. Position the ohmmeter probes into the fuel pump/fuel level sensor electrical connector and check the resistance. Use the 200-ohm scale on the ohmmeter. With the fuel tank completely full, the resistance should be about 160.0 ohms. With the fuel tank nearly empty, the resistance of the sensor should be about 15.0 ohms. If the readings are incorrect, replace the sensor. A more accurate check of the sensor can be made by removing it from the fuel tank and checking its resistance while manually operating the float arm. A more accurate check of the fuel level sensor can be performed with the assembly on the bench. Connect the ohmmeter probes to the connector and check the resistance of the sensor with the float positioned on "empty" and "full". Check for a smooth change in resistance as the float is moved. Remove the fuel tank. Remove the fuel pump module from the fuel tank. Remove the sensor mounting bolt(s) and harness connectors from the fuel pump module. Installation is the reverse of removal.