Without FFS

CIRCUIT DESCRIPTION
When you turn on the ignition switch, the control module enables the fuel pump relay which powers the fuel pump ON. The fuel pump remains ON as long as the engine is cranking or running and the control module receives ignition reference pulses. If there are no ignition reference pulses, the control module shuts the fuel pump OFF within 2 seconds after the ignition was switched to the ON position or if the engine stops.

The electric fuel pump is attached to the fuel sender assembly inside the left fuel tank. The in-tank fuel pump supplies fuel through a fuel feed pipe, and a fuel filter/fuel pressure regulator assembly, to the fuel rail. The fuel pump supplies fuel to the siphon jet pump in the right fuel tank. The siphon jet pump transfers fuel from the right fuel tank to the left fuel tank. The fuel pump provides fuel at a pressure greater than that needed by the fuel injectors. The fuel pressure regulator, part of the fuel filter, keeps the fuel available to the fuel injectors at a regulated pressure. Unused fuel returns to the left fuel tank by a separate fuel return pipe.

TEST DESCRIPTION

Steps 1-5:

Steps 6-8:

Steps 9-10:

Step 11:

Steps 12-14:

Step 15:

Step 16:

Steps 17-20:

Steps 21-23:

Steps 24-29:

The numbers below refer to the step numbers on the diagnostic table.
4. This step verifies that the vehicle is not out of fuel.
7. This step tests for an internal fuel leak.
10. This step tests for a loss of fuel pressure between the fuel feed pipe shut-off adapter and the fuel injectors.
11. This step tests for a loss of fuel pressure between the fuel feed pipe shut-off adapter and the fuel pump.
12. This step tests if the loss of fuel pressure is caused by the fuel pressure regulator, or by the check valve that is located in the fuel feed rear pipe.
15. This step determines if the fuel pressure regulator, or the fuel pump is the cause of the low fuel pressure.
16. This step verifies that there is an adequate supply of fuel to the siphon jet pump.
17. This step verifies the auxiliary fuel return rear pipe is not restricted.