Fuel Pump Checking, Engine Code BPS (Plastic Fuel Tank)

Fuel Pump Checking, Engine Code BPS (Plastic Fuel Tank)

Special tools, testers and auxiliary items required

• Wrench (3087) or (T10202)

• Fuel Inj pressure gauge-cis (VAG 1318)

• Pressure gauge adapter (VAG 1318/1)

• Adapter (VAG 1318/11)

• Adapter (VAG 1318/17)

• Torque wrench (40-200 Nm) (VAG 1332)

• Remote control (VAG 1348/3A)

• Connector test set (VAG 1594C)

• Voltage tester (VAG 1527B)

• Vehicle diagnosis, testing and information system (VAS 5051B) or multi-meter (VAG 1715 )

• Measuring container

=> [ Function and Voltage Supply, Checking ]

=> [ Delivery Quantity, Checking ]

=> [ Current Draw, Checking ]

=> [ Fuel Pump Check Valve, Checking ]

Function and Voltage Supply, Checking

• Battery voltage at least 11.5 volts

• Fuse for fuel pump in fuse holder OK

- Switch on ignition.

• Fuel pump must briefly start up audibly.

• Fuel pump runs quietly.

- Switch off ignition.

If Fuel Pump Does Not Start Up

- Fold the rear seat bench forward.

- Remove the cover from the fuel delivery unit.

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





- Connect the (VAG 1527B) using adapter cables from (VAG 1594C) to the outer terminals of the connector.





- Switch ignition on.

• Light Emitting Diode (LED) must light up briefly.

If LED does not light up briefly:

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

LED lights up briefly (voltage supply OK):

- Remove the fuel delivery unit. Refer to => [ Fuel Delivery Unit ] Removal and Replacement.

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

If no open circuits are found:

- Fuel pump is faulty, replace the fuel delivery unit. Refer to => [ Fuel Delivery Unit ] Removal and Replacement.

Delivery Quantity, Checking

• Voltage supply OK.

• Fuel pressure regulator and residual pressure OK. Refer to => [ Fuel Pressure Regulator and Residual Pressure Checking, Engine Code BPS ] Fuel Pressure Regulator and Residual Pressure Checking, Engine Code BPS

• Fuel filter OK.

- Remove the fuel filler cap from the fuel filler tube.

- Fold the rear seat bench forward.

- Remove the cover from the fuel delivery unit.

- Disconnect the 4 pin harness connector - arrow - from the fuel delivery unit.





- Connect the (VAG 1348/3A) with an adapter cable to terminal - 1 - of the fuel pump and to battery positive (+).





- Connect terminals - 4 - of the harness connector and fuel pump using an adapter cable from (VAG 1594C).

• Delivery rate of fuel pump is measured at 4 bar. Therefore, measure fuel pressure before measuring delivery rate. Refer to => [ Fuel Pressure Regulator and Residual Pressure Checking, Engine Code BPS ] Fuel Pressure Regulator and Residual Pressure Checking, Engine Code BPS.

CAUTION!
Fuel system is under pressure!

• Wear protective goggles and protective clothing to prevent injuries and contact with skin.

• Before loosening the line connection, place a cloth around the connection point. Then release pressure by carefully loosening the connection.

- Disconnect the return line - 1 - from the fuel pressure regulator.





• Press in the securing ring to disengage the fuel line.

- Connect the (VAG 1318/17) to the fuel pressure regulator and hold the other end of the (VAG 1318/17) in a measuring container.

- Operate the (VAG 1348/3A) approximately 5 seconds in order to fill the fuel filter.

- Empty the measuring container.

- Delivery rate of the fuel pump is dependent on voltage. Therefore connect a multi-meter to the battery.

- Operate the (VAG 1348/3A) for 30 seconds and measure the battery voltage.

- Compare the quantity of fuel delivered with specification.





*) Minimum delivery rate cm3/30 s

**) Voltage at fuel pump with engine off and pump running (approximately 2 volts less than battery voltage).

Example

During the test, a voltage of 12.5 volts is measured at the battery. Since the voltage at the pump is approximately 2 volts less than battery voltage, there is a minimum delivery rate of 580 cm3/30 s.

If the minimum delivery rate is not attained:

- Check supply line to filter for possible restrictions (kinks) or clogging.

If fuel line is OK:

- Check fuel delivery rate in front of fuel filter.

CAUTION!
Fuel system is under pressure!

• Wear protective goggles and protective clothing to prevent injuries and contact with skin.

• Before loosening the line connection, place a cloth around the connection point. Then release pressure by carefully loosening the connection.

- Disconnect supply line - 1 - from the fuel filter input.





• Press in the securing ring to disengage the fuel line.

- Connect the (VAG 1318) to the (VAG 1318/17) as shown.

- Connect the (VAG 1318/1) to the (VAG 1318/11) on the (VAG 1318) and hold it in a measuring container.

CAUTION!
Danger of spraying when opening shut off lever! Wear protective goggles and protective clothing to prevent injuries and contact with skin. Hold container in front of free connection of pressure measuring device.

- Open shut off lever on the (VAG 1318). Lever will point in direction of flow - A -.

- Operate the (VAG 1348/3A). Slowly close the shut off valve, until the (VAG 1318) shows 4 bar. From this point on do not move position of the shut off lever.

- Empty the measuring container.

- Operate the (VAG 1348/3A) again for 30 seconds. Compare the delivery rate with the value determined from the first measurement.

If the minimum delivery rate is now obtained:

- Replace the fuel filter.

If minimum delivery rate is again not obtained:

- Remove the fuel delivery unit and check the filter strainer for dirt.

Only if no malfunctions have been detected up to now:

- Replace the fuel delivery unit. Refer to => [ Fuel Delivery Unit ] Removal and Replacement.

- Reconnect all disconnected fuel lines.

- Bleed the fuel supply system. Refer to => [ Fuel System, Bleeding ] Description and Operation.

Delivery rate has been obtained, but malfunctions are still suspected in the fuel supply, for example sporadic loss of fuel supply:

- Check fuel pump current draw. Refer to => [ Current Draw, Checking ].

Current Draw, Checking

- Fold the rear seat bench forward.

- Remove the cover from the fuel delivery unit.

- Connect the current clamp - A - from the vehicle diagnosis, testing and information system (VAS 5051B) or the multi-meter (VAG 1715) to the wire - B - for contact 1 on the 4 pin connector.





- Start the engine and run at idle speed.

- Measure the current draw of the fuel pump.

• Specified value: Max. 9 amps.

• If malfunction in the fuel system is sporadic, test can also be performed during a road test, but a second person is required.

If the current draw is exceeded:

- Fuel pump is faulty, replace the fuel delivery unit. Refer to => [ Fuel Delivery Unit ] Removal and Replacement.

Fuel Pump Check Valve, Checking

- Fold the rear seat bench forward.

- Remove the cover from fuel delivery unit.

- Disconnect the 4 pin harness connector - arrow - from the fuel delivery unit.





- Connect the (VAG 1348/3A) with an adapter cable to terminal - 1 - of fuel pump and to battery positive (+).





- Connect terminals - 4 - of harness connector and fuel pump using an adapter cable from (VAG 1594 C).

CAUTION!
Fuel system is under pressure!

• Wear protective goggles and protective clothing to prevent injuries and contact with skin.

• Before loosening the line connection, place a cloth around the connection point. Then release pressure by carefully loosening the connection.

- Disconnect the supply line - 1 - from the fuel filter input.





• Press in the securing ring to disengage the fuel line.

- Connect the (VAG 1318) to the (VAG 1318/17) as shown.

- Connect the (VAG 1318/1) to the (VAG 1318/11) on the (VAG 1318) and hold it in a measuring container.

- Close the shut off lever on the (VAG 1318) (lever perpendicular to direction of flow, position - B -).

- Operate the (VAG 1348/3A) at short intervals, until a pressure of approximately 4 bar has built up.

CAUTION!
Danger of spraying when opening shut off lever; wear protective goggles and protective clothing to prevent injuries and contact with skin. Hold container in front of free connection of pressure measuring device.

- If pressure builds up too high, lower excess pressure by carefully opening the shut off lever.

- Watch pressure drop on the (VAG 1318).

• After 10 minutes the pressure must not drop below a 3 bar decrease.

If the pressure drops further:

- Check line connections for leaks.

If no fault is detected in the wiring:

- Fuel pump is faulty, replace the fuel delivery unit. Refer to => [ Fuel Delivery Unit ] Removal and Replacement.