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- Proceed to .


Diagnosis Procedure


1. CHECK FUEL PUMP RELAY POWER SUPPLY

1.Turn ignition switch OFF.
2.Disconnect ECM harness connector.
3.Turn ignition switch ON.
4.Check the voltage between ECM harness connector terminals.





Is the inspection result normal?
YES- GO TO 3.
NO- GO TO 2.

2. CHECK FUEL PUMP RELAY POWER SUPPLY CIRCUIT

1.Turn ignition switch OFF.
2.Disconnect IPDM E/R harness connector.
3.Check the continuity between ECM harness connector and IPDM E/R harness connector.





4.Also check harness for short to ground.
Is the inspection result normal?
YES- Perform the trouble diagnosis for power supply circuit.
NO- Repair or replace error-detected parts.

3. CHECK LOW FUEL PUMP POWER SUPPLY

1.Turn ignition switch OFF.
2.Reconnect ECM harness connector.
3.Disconnect fuel level sensor unit and fuel pump harness connector.
4.Turn ignition switch ON.
5.Check the voltage between fuel level sensor unit and fuel pump harness connector and ground.





Is the inspection result normal?
YES- GO TO 5.
NO- GO TO 4.

4. CHECK LOW FUEL PUMP POWER SUPPLY CIRCUIT

1.Turn ignition switch OFF.
2.Disconnect IPDM E/R harness connector.
3.Check the continuity between fuel level sensor unit and fuel pump harness connector and IPDM E/R harness connector.





4.Also check harness for short to ground.
Is the inspection result normal?
YES- Perform the trouble diagnosis for power supply circuit.
NO- Repair or replace error-detected parts.

5. CHECK LOW FUEL PUMP GROUND CIRCUIT

1.Turn ignition switch OFF.
2.Check the continuity between fuel level sensor unit and fuel pump harness connector and ground.





3.Also check harness for short to power.
Is the inspection result normal?
YES- GO TO 6.
NO- Repair or replace error-detected parts.

6. CHECK LOW FUEL PUMP

Check the low fuel pump. .
Is the inspection result normal?
YES- Check intermittent incident. Intermittent Incident.
NO- Replace fuel level sensor unit and fuel pump. Exploded View.


Component Inspection


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.
3.Check resistance between fuel level sensor unit terminals as follows.





Is the inspection result normal?
YES- INSPECTION END
NO- Replace fuel level sensor unit. Exploded View.