K 1500 Yukon Denali AWD V8-6.0L VIN U (2002)
Fuel Pressure: Testing and Inspection
Fuel System Diagnosis
SYSTEM 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 fuel tank stores the fuel supply. The electric fuel pump supplies fuel through an in-line fuel filter to the fuel injection system. The pump provides
fuel at a higher rate of flow than is needed by the fuel injection system. The fuel pressure regulator maintains the correct fuel pressure to the fuel
injection system. A separate pipe returns unused fuel to the fuel tank.
TEST DESCRIPTION
Steps 1-2
