Fuel Pumps, Checking

Fuel Pumps, Checking

Special tools, testers and auxiliary items required

• Voltage Tester (V.A.G 1527 B)

• Multi-Meter (V.A.G 1526 C) or (V.A.G 1715)

• Connector Test Set (V.A.G 1594 C)

Test Conditions:

• The fuses must be OK

• Battery voltage must be at least 11.5 bolts

• All electrical consumers such as, for example, lights and rear window defroster must be turned off.

Function and Voltage Supply, Checking

- Fold the rear seat bench forward

- Briefly operate the starter. The fuel pumps must run audibly.

- Turn off the ignition.

If the fuel pumps do not start up:

Vehicles through 24 November 2006:

For vehicles from 27 November 2006.

- Cut open the carpet from point - A - to point - B - in the precut area - arrows -.






Right Side of Vehicle:

- Remove the cover nuts - 1 -. Remove the backrest bearing - 2 - or bracket if necessary.





Left Side of Vehicle:

- Remove the bolts - 1 -.

- Then, remove the nuts - 2 -. The bracket will have to be pressed upward slightly to remove one of the nuts.






Vehicles from 27 November 2006:

- Remove the rear seat bench.

Continuation for all Vehicles:

Check the voltage supply of each individual fuel pump as follows:

- Disconnect the 4-pin harness connector from the right flange of the fuel delivery unit.

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






- Turn on the ignition, the Light Emitting Diode (LED) must light up for approximately 2 seconds.

If the LED does not light up:

- Check activation of the fuel pump relay and check the wires for a open and/or short circuit.

If the LED lights up (voltage supply OK):

- Remove the right fuel delivery unit. Refer to => [ Fuel Delivery Unit, Fuel Level Sensor and Suction Jet Pump ] Fuel Delivery Unit, Fuel Level Sensor and Suction Jet Pump.

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

If no open circuits are found:

- The right fuel delivery unit is faulty. Replace the fuel delivery unit. Refer to => [ Fuel Delivery Unit, Fuel Level Sensor and Suction Jet Pump ] Fuel Delivery Unit, Fuel Level Sensor and Suction Jet Pump.

- Repeat the test on the left fuel delivery unit.

Current Pickup of Fuel Pumps, Checking

- Check the current draw of each individual fuel pump as follows:

- Connect the current clamp from multi-meter (V.A.G 1715) to the wire of the 4-pin connector contact 1 - arrow - from the wiring harness to the right fuel delivery unit.






- Start the engine and run at idle speed.

- Measure the fuel pump current draw: Specified value: Max. 8 amperes.

If the current draw is exceeded:

- The right fuel delivery unit is faulty. Replace the fuel delivery unit. Refer to => [ Fuel Delivery Unit, Fuel Level Sensor and Suction Jet Pump ] Fuel Delivery Unit, Fuel Level Sensor and Suction Jet Pump.

- Repeat the test on the left fuel delivery unit.