Audi Cars 1999-05

Fuel Pump

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Removal & Installation




CAUTION
Observe all safety precautions while performing the procedure.


CAUTION
Determine the correct radio anti-theft coding before disconnecting the battery.

  1. With the ignition switch off, disconnect the battery negative cable.
  2.  
  3. Remove the fuel pump access cover in luggage compartment floor
  4.  



Click image to see an enlarged view

Fig. Fuel pump access cover removal

  1. Disconnect the harness connector, fuel supply and return hose from the flange.
  2.  
  3. Remove the ring nut with spanner wrench.
  4.  
  5. Remove the flange and sealing ring from the fuel tank opening.
  6.  
  7. Loosen the fuel pump module from bayonet connection by turning it to the left and removing it from the tank opening.
  8.  


CAUTION
If the fuel pump module is still filled with fuel, empty before installation.

To install:

  1. Installation is in the reverse order of removal procedure. Note the following during installation:
  2.  
    1. When installing the fuel pump module, make certain the fuel sensor arm is not bent.
    2.  
    3. Lubricate the flange seal with fuel before installing.
    4.  
    5. Ensure the proper installation position of the fuel pump module flange and attaching parts, as shown.
    6.  
    7. When the fuel pump module is correctly installed, the fuel gauge sender points to the direction of travel 'A', as shown.
    8.  




Click image to see an enlarged view

Fig. Positioning the fuel pump module

The fuel pump is located in the fuel tank. It is recommended that the fuel tank not be filled more than 1 / 3 full. If necessary the fuel must be drained using an approved fuel cart.

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Make certain to follow precautions and properly relieve fuel pressure.
  4.  
  5. Disconnect the negative battery cable.
  6.  
  7. Lift the cargo area trim and locate the inspection cover for the fuel pump and gauge sending unit assembly.
  8.  
  9. Mark the supply and return lines for reassembly.
  10.  
  11. Disconnect the electrical connector.
  12.  
  13. Loosen the union nut using tool No. 3217 or equivalent.

    Click image to see an enlarged view

    Fig. Tool No. 3217 or equivalent is used to loosen and tighten the union nut on the fuel tank for access to the fuel pump and fuel level sending unit

  14.  
  15. Make alignment marks before removing and then lift the fuel gauge sending unit assembly and disconnect the level connector and the fuel return line.
  16.  
  17. Using tool No. 3307 or equivalent, turn the fuel pump module to the left (counterclockwise) about 15 degrees.

    Click image to see an enlarged view

    Fig. Tool No. 3307 or equivalent is used to remove and install the fuel pump in the fuel tank

  18.  
  19. Carefully remove the fuel pump from the fuel tank.
  20.  
  21. Use caution and catch excess fuel in a container.
  22.  
  23. Remove fuel pump supply hose and the electrical connectors and remove the fuel pump.
  24.  

To install:

  1. The installation is reverse of the removal procedure.
  2.  
  3. Install the flange cover using a new O-ring and lubricate the O-ring with fuel.
  4.  
  5. Tighten the union nut using tool No. 3217 ore equivalent to 44 ft. lbs. (60 Nm).
  6.  
  7. Connect the negative battery cable.
  8.  
  9. Enter the radio security code.
  10.  

The fuel pump is located in the fuel tank. It is recommended that the fuel tank not be filled more than 1 / 3 full. If necessary the fuel must be drained using an approved fuel cart.

  1. Before servicing the vehicle, refer to the precautions section.
  2.  
  3. Properly relieve fuel pressure.
  4.  
  5. Remove or disconnect the following:

    Negative battery cable
     
    Inspection cover by lifting the cargo area trim
     

  6.  
  7. Mark the fuel pump/gauge sending unit assembly supply and return lines for reassembly.
  8.  
  9. Remove or disconnect the following:

    Electrical connector
     
    Union nut by loosening it using tool 3217

    Click image to see an enlarged view

    Fig. Tool 3217 is used to loosen and tighten the union nut on the fuel tank for access to the fuel pump and fuel level sending unit

     



    Fuel pump/gauge sending unit assembly by matchmarking it
     
    Level connector and the fuel return line
     

  10.  
  11. Using tool 3307, turn the fuel pump module to the left (counterclockwise) about 15 degrees.

    Click image to see an enlarged view

    Fig. Tool 3307 is used to remove and install the fuel pump in the fuel tank

  12.  
  13. Remove or disconnect the following:

    Fuel pump supply hose
     
    Electrical connectors
     
    Fuel pump
     

  14.  

To install:

  1. The installation is reverse of the removal procedure.
  2.  
  3. Install or connect the following:

    Flange cover using a new O-ring lubricated the O-ring with fuel
     
    Union nut using tool 3217. Torque it to 59 ft. lbs. (80 Nm)
     
    Negative battery cable
     

  4.  
  5. Start the vehicle, check for leaks and repair if necessary.
  6.  

Testing



See procedure under 'Electric Fuel Pump' heading

Circuit Inspection
Diagnosis & Testing
  1. To begin testing the fuel pump electrical circuit, first check that the battery is at a full state of charge.
  2.  


NOTE
Do NOT forget to check the condition of the fuse in the fuse box. If it is blown, the fuel pump will not receive the necessary electricity to operate.

  1. Remove the access panel from the fuel pump.
  2.  
  3. Turn the ignition key to the ON position and have a helper listen for the pump to begin running. If the system is operating correctly, the pump should run for a short period and then shut off. If the pump does not run, continue on to the following steps.
  4.  
  5. Remove the fuel pump relay and operate the pump using a remote by-pass switch. If the pump runs after performing this test, proceed to the next diagnostic step in this procedure.
  6.  
  7. Install the fuel pump relay again.
  8.  
  9. Check for proper activation of the fuel pump relay, using an appropriate circuit tester.
  10.  
  11. If the fuel pump does not run when the relay is by-passed follow the following procedures:
  12.  
    1. Remove luggage compartment floor cover.
    2.  
    3. Disconnect the fuel pump wiring connector.
    4.  
    5. Remove the fuel pump relay and install a remote starter, VAG 1348/3A, with adapter wire, to connector and battery plus (+) terminal.
    6.  

  13. Connect an LED tester, VAG 1527B (or equivalent), to outer terminal of connector, using jumper wires from test kit.
  14.  

If LED does not light up, check the circuit wiring for faults. Repair as necessary.

If LED lights up, loosen flange nut with special spanner wrench, and then check the wiring and connections between the flange and fuel pump assembly.



If no open circuit is found, the fuel pump is defective and needs to be replaced.
 

Fuel Transfer Pump

Testing of the transfer pump is done by measuring the delivery rate of the pump. To accomplish this test you will need a measuring container and fuel hose (max. 14 in)

  1. Remove the access cover to the transfer pump.
  2.  
  3. Remove the fuel filler cap
  4.  
  5. Bypass the fuel pump relay to operate the pump. An assistant should be available to assist with this test.
  6.  
  7. Make a jumper wire at least 14 in long of 14-gauge wire. For safety, include an in-line fuse holder (20 amp).
  8.  
  9. Avoid damage to the relay panel sockets. The ends of the jumper should be flat-blade connectors that are the same size as the terminals on the relay.
  10.  



Click image to see an enlarged view

Fig. Passat fuse/relay panel. Fuel pumps are powered via fuse No. 18 and relay No. 12.


NOTE
The fuel pump should begin to operate. If not, test for proper current to the fuel transfer pump connector with a test light. If current is available and the pump will not start pump, the pump is defective. If pump begins to operate and fuel begins to flow, continue with the delivery rate test.

  1. With container and hose measure the fuel volume.
  2.  
    1. Length of test. 10 seconds
    2.  
    3. Minimum fuel quantity 10.1 fl. Oz. (300 cc)
    4.  



NOTE
If the pump fails the above quantity test, before replacement, remove the pump and verify that the strainer/filter is clean. If the strainer/filter is dirty, clean and retest.

  1. Reinstall components disconnected/removed for testing.
  2.  

Main Fuel Pump

Testing of the main fuel pump is done by measuring the delivery rate of the pump. To accomplish this test you will need a measuring container and fuel hose (max. 14 in).


NOTE
On CIS systems the main fuel pump is located under the vehicle in front of the rear axle or in front of the tank on the right side.

  1. Disconnect the fuel return line at the connection in the engine compartment near the right front suspension strut tower.
  2.  
  3. Connect a voltmeter to measure the actual voltage at the fuel pump connector.
  4.  
  5. Bypass the fuel pump relay to operate the pump.
  6.  
  7. With container and hose measure the fuel volume. Run the test for 30 seconds and measure the fuel volume.
  8.  


NOTE
The minimum fuel delivery depends on voltage supplied to the pump. See chart for minimum fuel quantity vs. voltage.



Click image to see an enlarged view

Fig. Fuel pump voltage vs. pump flow chart


NOTE
For all other VW Passat 1994-2000 and Audi A4 1996-2000, see procedures under 'Electric Fuel Pump' heading.

 
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