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 (1) with two fingers.





Is the inspection result normal?
YES - INSPECTION END
NO - SEE Diagnosis Procedure.




Wiring Diagram









Diagnosis Procedure
1.CHECK FUEL PUMP POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Turn ignition switch ON.





4. Check the voltage between ECM harness connector and ground.





Is the inspection result normal?
YES - GO TO 4.
NO - GO TO 2.
2.CHECK FUEL PUMP POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R harness connector E46.
3. Turn ignition switch ON.





4. Check the voltage between IPDM E/R harness connector and ground.





Is the inspection result normal?
YES - GO TO 4.
NO - GO TO 10.
3.DETECT MALFUNCTIONING PART
Check the following.
- Harness or connectors E8, F8.
- Harness for open or short between ECM and IPDM E/R
- Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK FUEL PUMP POWER SUPPLY CIRCUIT-III
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
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 8.
NO - GO TO 5.
5.CHECK FUSE
1. Turn ignition switch OFF.
2. Disconnect 15 A fuse (No. 48) from IPDM E/R.
3. Check 15 A fuse.
Is the inspection result normal?
YES - GO TO 6.
NO - Replace15 A fuse.
6.CHECK FUEL PUMP POWER SUPPLY CIRCUIT-IV
1. Disconnect IPDM E/R harness connector E45.
2. Check the continuity between IPDM E/R harness connector and "fuel level sensor unit and fuel pump" harness connector.





3. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES - GO TO 10.
NO - GO TO 7.
7.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E7, M69
- Harness connectors M12, B101
- Harness for open or short between IPDM E/R and "fuel level sensor unit and fuel pump"
- Repair open circuit or short to power in harness or connectors.
8.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 9.
NO - Repair open circuit or short to power in harness or connectors.
9.CHECK FUEL PUMP
SEE Component Inspection.
Is the inspection result normal?
YES - GO TO 10.
NO - Replace "fuel level sensor unit, fuel filter and fuel pump". Removal and Installation.
10.CHECK INTERMITTENT INCIDENT
Trouble Diagnosis For Intermittent Incident.
Is the inspection result normal?
YES - Replace IPDM E/R. 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 per the following.





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