Diagnosis And Testing - Fuel Level Sending Unit

Fig 1: Identifying Fuel Level Sending Unit Components

Courtesy of DAIMLERCHRYSLER CORP.

1 - FUEL LEVEL SENDER

2 - FUEL LEVEL SENSOR

3 - CONTACTS

4 - POTENTIOMETER

5 - FUEL PRESSURE SENSOR

The Fuel Level Sending Unit (1) contains a variable resistor (3) (track). As the float (2) moves up or down, electrical resistance will change. Refer to INSTRUMENT PANEL for Fuel Gauge testing. To test the gauge sending unit only, it must be removed from vehicle. The sending unit is a part of the Fuel Level Sending Unit/Sensor, located and accessible at the top of the Fuel Tank. Measure the resistance across the sending unit terminals. With float (2) in up position, resistance should be 20 ohms (+/- 5%). With float (2) in down position, resistance should be 270 ohms (+/- 5%).