Low Pressure Fuel Pump

LOW PRESSURE FUEL PUMP

Component Function Check


1. CHECK FUEL PUMP FUNCTION

1.Turn ignition switch ON.
2.Pinch fuel feed hose with two fingers.
NOTE:
Fuel pressure pulsation should be felt on the fuel feed hose for 1 second after ignition switch is turned ON.
Is the inspection result normal?
YES- INSPECTION END
NO-.


Diagnosis Procedure


1. CHECK FPCM POWER SUPPLY CIRCUIT

1.Turn ignition switch OFF.
2.Disconnect FPCM harness connector.
3.Turn ignition switch ON.
4.Check the voltage between FPCM harness connector and ground.





Is the inspection result normal?
YES- GO TO 2.
NO- Perform the trouble diagnosis for power supply circuit. Power Supply And Ground Circuit.

2. CHECK FPCM GROUND CIRCUIT

1.Turn ignition switch OFF.
2.Check the continuity between FPCM harness connector and ground.





Is the inspection result normal?
YES- GO TO 3.
NO- Repair open circuit or short to power in harness or connectors.

3. CHECK FPCM INPUT AND OUTPUT CIRCUIT

1.Disconnect ECM harness connector.
2.Check the continuity between FPCM harness connector and ECM harness connector.





3.Also check harness for short to ground and to power.
Is the inspection result normal?
YES- GO TO 4.
NO- Repair or replace error-detected parts.

4. CHECK FUEL PUMP CONTROL CIRCUIT

1.Disconnect fuel level sensor unit and fuel pump (main) harness connector.
2.Check the continuity between FPCM harness connector and fuel level sensor unit and fuel pump (main)
harness connector.





3.Also check harness for short to ground and to power.
Is the inspection result normal?
YES- GO TO 5.
NO- Repair or replace error-detected parts.

5. CHECK LOW PRESSURE FUEL PUMP

.
Is the inspection result normal?
YES- GO TO 6.
NO- Replace low pressure fuel pump. Removal And Installation.

6. CHECK FPCM

.
Is the inspection result normal?
YES- Check intermittent incident. Intermittent Incident.
NO- Replace FPCM. Service and Repair.


Component Inspection (Low Pressure Fuel Pump)


1. CHECK FUEL PRESSURE REGULATOR

1.Turn ignition switch OFF.
2.Check low fuel pressure. Testing and Inspection.
Is inspection result normal?
YES- INSPECTION END
NO- GO TO 2.

2. CHECK LOW PRESSURE FUEL PUMP

1.Turn ignition switch OFF.
2.Disconnect fuel level sensor unit and fuel pump (main).
3.Check resistance between fuel level sensor unit and fuel pump (main) terminals as follows.





Is the inspection result normal?
YES- INSPECTION END
NO- Replace fuel level sensor unit and fuel pump (main). Exploded View.


Component Inspection (FPCM)


1. CHECK FUEL PUMP CONTROL MODULE (FPCM)

1.Check the voltage between FPCM terminals under the following conditions.





Is the inspection result normal?
YES- INSPECTION END
NO- Replace FPCM. Service and Repair.