Fuel Level Sensor, Checking

Special tools and workshop equipment required

Hand-Held Multimeter V.A.G 1526C
Connector Test Set V.A.G 1594C

Procedure

-- Remove rear seat bench. Refer to Removal and Installation .

-- Unclip the retainers -arrows- of the cover for sealing flange.

Fig 1: Identifying Cover From Fuel Delivery Unit

Courtesy of AUDI OF AMERICA, LLC

-- Disconnect electrical harness connector -arrow- at locking flange.

Fig 2: Identifying Fuel Delivery Unit Connector

Courtesy of AUDI OF AMERICA, LLC

Vehicles through 10.2004:

NOTE:

On vehicles with 2-wire sensor technology, the connector for fuel level sensor -G- is equipped with 4 terminals.

-- Connect multimeter between terminal -2- and -3- for resistance measurement.

Fig 3: Fuel Delivery Unit Connector Pins

Courtesy of AUDI OF AMERICA, LLC

Fuel level sensor -G- installed:

Sensor at lower stop: approximately 270 Ω.
Sensor at upper stop: approximately 70 Ω.

NOTE:

To check resistance values tank full or tank empty, the fuel delivery unit must be removed, refer to FUEL DELIVERY UNIT and the sensor floater must be placed in upper or lower end position.

If measured value is 0 Ω there is a short circuit. If measured value is ∞ Ω there is and open circuit in the wiring.

With fuel level sensor removed, the following values are obtained because of the greater deflection of the floater arm:

Fuel level sensor removed:

Sensor at lower stop: approximately 290 Ω.
Sensor at upper stop: approximately 54 Ω.

Assembly is in the reverse order of removal, note the following:

-- Install rear seat bench. Refer to Removal and Installation .

Vehicles from 10.2004:

NOTE:

On vehicles with 3-wire sensor technology, the connector for fuel level sensor is equipped with 5 terminals.

-- Connect multimeter between terminal -2- and -3- for resistance measurement.

Fig 4: Fuel Delivery Unit Connector Pins

Courtesy of AUDI OF AMERICA, LLC

Fuel level sensor installed:

Sensor at lower stop: approximately 270 Ω.
Sensor at upper stop: approximately 70 Ω.

NOTE:

To check resistance values tank full or tank empty, the fuel delivery unit must be removed FUEL DELIVERY UNIT and the sensor floater must be placed in upper or lower end position.

If measured value is 0 Ω there is a short circuit. If measured value is ∞ Ω there is and open circuit in the wiring.

With fuel level sensor removed, the following values are obtained because of the greater deflection of the floater arm:

Fuel level sensor removed:

Sensor at lower stop: approximately 290 Ω.
Sensor at upper stop: approximately 50 Ω.

-- Connect multimeter between terminal -3- and -4- for resistance measurement.

Fuel level sensor installed or removed:

Arbitrary sensor position: approximately 340 Ω.

Assembly is in the reverse order of removal, note the following:

-- Install rear seat bench. Refer to Removal and Installation .