GM Service Manual Online
For 1990-2009 cars only

Special Tools

    • EN-48279 Main Fuel Pump Locking Ring Remover/Installer
    • EN-48278 Sub Fuel Pump Locking Ring Remover/Installer

Removal Procedure

    Warning: Refer to Battery Disconnect Warning in the Preface section.


    Object Number: 1760006  Size: SH
  1. Disconnect the negative battery cable.
  2. Fold the rear seat.
  3. Lift up the carpet and the insulation.
  4. Remove the primary and secondary fuel tank module access covers.

  5. Object Number: 1760008  Size: SH
  6. Disconnect the electrical connector at the secondary fuel tank module assembly.

  7. Object Number: 1785018  Size: SH
  8. Install the EN-48278 to the secondary fuel tank module and turn it counterclockwise.
  9. Remove the secondary fuel tank module lock ring.
  10. Note: Use care when handling the primary/secondary fuel tank module to prevent damage and incorrect fuel level readings.

    Note: O-ring should not be contaminated by fuel.

  11. Remove the secondary fuel tank module assembly and the O-ring from the fuel tank.

  12. Object Number: 1760009  Size: SH
  13. Disconnect the primary fuel pump-to-secondary fuel pump hose.

  14. Object Number: 1820494  Size: SH
  15. Disconnect the electrical connector at the primary fuel tank module assembly.
  16. Disconnect the fuel feed and return line.

  17. Object Number: 1785005  Size: SH
  18. Install the EN-48279 to the primary fuel tank module and turn it counterclockwise.
  19. Remove the primary fuel tank module lock ring.
  20. Note: Be careful not to damage the fuel sender for the correct fuel leveling while removing the fuel pump assembly from the fuel tank.

    Note: O-ring should not be contaminated by fuel.

  21. Remove the primary fuel tank module assembly and the O-ring from the fuel tank.

Installation Procedure


    Object Number: 1760013  Size: SH
  1. Clean all of the mating surfaces on the both fuel tank modules and fuel tank.
  2. Note: Do not reuse the primary or secondary fuel tank module O-rings.

    Note: For ease of connecting the primary fuel tank module-to-secondary fuel tank module connecting hose, install the primary fuel tank module assembly first.

    Note: Be sure that the arrow on the primary fuel tank module assembly is aligned with the arrow on the fuel tank.

    Note: Be careful not to damage the fuel sender for the correct fuel leveling while removing the fuel pump assembly from the fuel tank.

  3. Position the new O-ring and the primary fuel tank module first into the fuel tank in the same location as removed.

  4. Object Number: 1760009  Size: SH
  5. Pull the primary fuel tank module -to-secondary fuel tank module connecting hose to the secondary fuel tank module assembly and connect the hose.

  6. Object Number: 1760018  Size: SH
  7. Position the new O-ring and the secondary fuel tank module into the fuel tank in the same location as removed.

  8. Object Number: 1760008  Size: SH
  9. Install the lock ring by turning EN-48278 clockwise.
  10. Connect the electrical connector at the secondary fuel tank module.

  11. Object Number: 1820494  Size: SH
  12. Install the primary fuel tank module lock ring by turning EN-48279 clockwise.
  13. Connect the electrical connector.
  14. Connect the fuel feed and return lines.

  15. Object Number: 1760006  Size: SH
  16. Install the access covers.
  17. Connect the negative battery cable.
  18. Perform an operational check of the fuel pump.
  19. Fold the rear seat back to the original position.