The level sensor is a variable resistor. Its resistance changes with the amount of fuel in the tank. A float attached to the sensor moves as the fuel level changes. To test the level sensor, connect an ohmmeter across the sensor signal and sensor ground terminals of the fuel pump module connector. Move the float over the entire range to the positions shown in the resistance chart and record the resistance at each end point. Replace the level sensor if the resistance is not within specifications or an open circuit is noted during the entire range inspection.