GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Saturn 🢒 2002 🢒 L100/L200/LW200 🢒 Preface 🢒 Cautions and Notices 🢒 Fuel Pressure Relief

Tools Required

SA9127E Gage Bar Set

Caution: Refer to Relieving Fuel Pressure Caution in the Preface section.

Prior to servicing any fuel system components, such as the fuel rail, injectors, filter, pressure regulator, fuel tank, fuel pump module, etc., any pressure built up in the system must be relieved. There are 2 preferred methods:

  1. Start and run vehicle then disable the fuel pump with the scan tool.

    2. This method is the cleanest since no fuel, under pressure, will be present at any fitting or connection that needs to be serviced.

    This method is preferred when removing any components of the fuel system that require disconnecting fuel lines. If performance tests are to be run on the system underhood, procedure 2 will be preferable since the SA9127E will also be required for the testing.

    This method is also preferable to disconnecting the fuel pump relay since no DTCs will be set and there is no concern about voltage spikes to the ECM if the relay should be installed with the key ON.

    1.1. Connect the scan tool and start the vehicle.
    1.2. Turn the scan tool ON and locate Special Functions.
    1.3. Select Powertrain.
    1.4. Select Fuel System.
    1.5. Select Fuel Pump.
    1.6. Command the fuel pump OFF.
    1.7. The engine will die in 3-5 seconds. Turn the key OFF, and proceed with component removal/installation.

    Object Number: 894302 Size: SH
  2. Bleed pressure at the service test port.

    3. This method will require collection of fuel as pressure is relieved. Use of a suitable container is required.

    Caution: Refer to Gasoline/Gasoline Vapors Caution in the Preface section.

    2.1. Locate the service test port on the fuel rail and remove the protective cap.
    2.2. Connect the gage bar 53476 to the fuel gage pressure adapter 309725 using a flexible hose from the SA9127E .
    2.3. Make sure the needle valve on the pressure adapter is closed (OFF).

            Notice: Do not use any tools to tighten the adapter to the fuel line pressure port. If the adapter will not seal with finger tightening, then the seal is defective or damaged and needs to be replaced. Excessive torque on the adapter will damage the fuel line test port.

    2.4. Connect the pressure adapter to fuel line test port.
    2.5. Route the drain hose from the pressure adapter into a suitable container or route the fuel back to the fuel tank.
    2.6. Open the valve on the pressure adapter and bleed off the pressure and fuel.