Fuel Pump, Checking

Fuel Pump, Checking

Special tools, testers and auxiliary items required

• Voltage tester (V.A.G 1527 B)

• Connector test set (V.A.G 1594C)

• Vehicle diagnosis, testing, and information system (VAS 5051B)

Test Conditions

• The fuses must be OK.

• The battery voltage must be at least 11.5 Volts.

• All electrical consumers like, for example, lights and rear window heating, must be switched off.

Function and Voltage Supply, Checking

- Switch ignition on.

• Fuel Pump (FP) must briefly start up audibly.

• Fuel Pump (FP) runs quietly.

- Switch off ignition.

If Fuel Pump (FP) Does Not Start Up

- Remove seat bench

- Unclip cover - 1 - from fuel delivery unit. Arrow - 2 - points in direction of travel.





- Disconnect the connector - 1 -.





- Connect voltage tester (V.A.G 1527 B) using adapter cables from connector test kit (V.A.G 1594C) to outer terminals of connector.





- Switch ignition on.

• LED must light up briefly.

If LED does not light up briefly:

- Locate and repair open circuit in wiring using wiring diagram.

LED lights up briefly (voltage supply OK):

- Fuel delivery unit, removing => [ Fuel Delivery Unit ] Fuel Delivery Unit.

- Check if the electrical wiring between the flange and fuel pump is connected and has continuity.

If no open circuits are found:

- Replace fuel delivery unit => [ Fuel Delivery Unit ] Fuel Delivery Unit.

Fuel Pump Current Draw, Checking

- Remove seat bench

- Unclip cover - 1 - from fuel delivery unit. Arrow - 2 - points in direction of travel.





- Connect current probe - A - of vehicle diagnosis, testing and information system (VAS 5051B) on cable - B - to terminal 1 of 5-pin harness connector.





- Start the engine and run at idle speed.

- Measure Fuel Pump (FP) current draw:

• Specified value: max. 7.5 amps.

- If the measured value is greater than the specified value:

- Replace fuel delivery unit => [ Fuel Delivery Unit ] Fuel Delivery Unit.