Fuel Pump

FUEL PUMP

Description


SYSTEM 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 DESCRIPTION






A turbine type design fuel pump is used in the fuel tank.


Diagnosis Procedure


1. CHECK OVERALL 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.

OK or NG
OK-INSPECTION END
NG- GO TO 2.

2. CHECK FUEL PUMP POWER SUPPLY CIRCUIT-I

1.Turn ignition switch OFF.
2.Disconnect ECM harness connector.
3.Turn ignition switch ON.





4.Check voltage between ECM terminal 113 and ground with
CONSULT or tester.
Voltage: Battery voltage
OK or NG
OK- GO TO 5.
NG- GO TO 3.

3. CHECK FUEL PUMP POWER SUPPLY CIRCUIT-II






Check voltage between IPDM E/R terminal 46 and ground with
CONSULT or tester.
Voltage: Battery voltage
OK or NG
OK- GO TO 4.
NG- GO TO 9.

4. DETECT MALFUNCTIONING PART

Check harness for open or short between IPDM E/R and ECM.
- Repair harness or connectors.

5. CHECK FUSE

1.Turn ignition switch OFF.
2.Disconnect 15 A fuse (No. 48).
3.Check 15 A fuse.
OK or NG
OK- GO TO 6.
NG- Replace fuse.

6. CHECK FUEL PUMP POWER SUPPLY AND GROUND CIRCUIT FOR OPEN AND SHORT

1.Turn ignition switch OFF.





2.Disconnect "fuel level sensor unit and fuel pump" harness connector.
3.Disconnect IPDM E/R harness connector E119.
4.Check harness continuity between IPDM E/R terminal 13 and
"fuel level sensor unit and fuel pump" terminal 1, "fuel level sensor unit and fuel pump" terminal 3 and ground.
Refer to Wiring Diagram.
Continuity should exist.
5.Also check harness for short to ground and short to power.
OK or NG
OK- GO TO 8.
NG- GO TO 7.

7. DETECT MALFUNCTIONING PART

Check the following.
- Harness connectors E41, C1
- Harness for open or short between fuel pump and IPDM E/R
- Harness for open or short between fuel pump and ground
- Repair open circuit or short to ground or short to power in harness or connectors.

8. CHECK FUEL PUMP

.
OK or NG
OK- GO TO 9.
NG- Replace "fuel level sensor unit and fuel pump".

9. CHECK INTERMITTENT INCIDENT

Intermittent Incident.
OK or NG
OK- Replace IPDM E/R.
NG- Repair or replace harness or connectors.


Component Inspection


FUEL PUMP

1.Disconnect "fuel level sensor unit and fuel pump" harness connector.





2.Check resistance between fuel level sensor unit and fuel pump terminals 1 and 3.

Resistance: 0.2 - 5.0 Ohms [at 25�C (77�F)]