Fuel Pump: Testing and Inspection

FUEL PUMP

Description






The ECM activates the fuel pump for several seconds after the ignition switch is turned ON to improve engine start ability. If the ECM receives a engine speed signal from the camshaft position sensor (PHASE), it knows that the engine is rotating, and causes the pump to operate. If the engine speed signal is not received when the ignition switch is ON, the engine stalls. The ECM stops pump operation and prevents battery discharging, thereby improving safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump relay, which in turn controls the fuel pump.







Component Function Check


1. CHECK FUEL PUMP FUNCTION

1.Turn ignition switch ON.
2.Pinch fuel feed hose with two fingers.

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" .


Diagnosis Procedure


1. CHECK FUEL PUMP RELAY CONTROL SIGNAL

1.Turn ignition switch ON.
2.Check the voltage between ECM harness connector.





*1: Except for California
*2: For California
Is the inspection result normal?
YES- GO TO 3.
NO- GO TO 2.

2. CHECK FUEL PUMP RELAY CONTROL SIGNAL CIRCUIT

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





*1: Except for California
*2: For California
5.Also check harness for short to ground and to power.
Is the inspection result normal?
YES- GO TO 7.
NO- Repair or replace error-detected parts.

3. CHECK FUEL PUMP POWER SUPPLY

1.Turn ignition switch OFF.
2.Disconnect "fuel level sensor unit and fuel pump" harness connector.
3.Turn ignition switch ON.
4.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 FUEL PUMP POWER SUPPLY CIRCUIT

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





4.Also check harness for short to ground and to power.
Is the inspection result normal?
YES- GO TO 7.
NO- Repair or replace error-detected parts.

5. CHECK FUEL PUMP GROUND CIRCUIT

1.Check the continuity between "fuel level sensor unit and fuel pump" and ground.





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

6. CHECK FUEL PUMP

Refer to "Component Inspection" .
Is the inspection result normal?
YES- GO TO 7.
NO- Replace "fuel level sensor unit and fuel pump". Refer to "Removal and Installation" Removal And Installation.

7. CHECK INTERMITTENT INCIDENT

Perform "Intermittent Incident" Intermittent Incident.
Is the inspection result normal?
YES- Replace IPDM E/R. Refer to "Removal and Installation" Service and Repair.
NO- Repair or replace harness or connectors.


Component Inspection


1. CHECK FUEL PUMP

1.Turn ignition switch OFF.
2.Disconnect "fuel level sensor unit and fuel pump" harness connector.
3.Check resistance between "fuel level sensor unit and fuel pump" terminals as follows.





Is the inspection result normal?
YES- INSPECTION END
NO- Replace "fuel level sensor unit and fuel pump". Refer to "Removal and Installation" Removal And Installation.