Fuel Level Sensor: Testing and Inspection
WITH SENSOR IN TANK -- FULL RANGE TEST1. Sending units and wiring can be checked by grounding the connector leads, at the sending unit, in the vehicle.
2. With the ignition in the ON position, a grounded input will cause the fuel or temperature gauge to read at or above maximum.
WITH SENSOR REMOVED FROM TANK
Fig. 6 Level Sensor Diagnosis:
NOTES:
- This procedure tests the resistance of the level sensor itself. It does not test the level sensor circuit.
- The level sensor is a variable resistor. Its resistance changes with the amount of fuel in the tank. The float arm attached to the sensor moves as the fuel level changes.
To test the level sensor:
1. Connect an ohmmeter across the sensor signal and sensor ground terminals of the fuel pump module connector.
2. Move the float lever to the positions shown in the resistance chart.
3. Measure the distance from the bottom of the float.
- Record the resistance at each point.
- The ohmmeter could show an open circuit if the contact on the bottom of the float arm does not touch the ribbed surface on the level sensor.
- Replace the level sensor if the resistance is not within specifications.