FUEL PUMP CIRCUIT

/ 9-2X (9346) / 2005 / 2. Engine / ENGINE (DIAGNOSTICS), 2.5i / Diagnostics for Engine Starting Failure / Fault diagnosis, general / FUEL PUMP CIRCUIT

FUEL PUMP CIRCUIT

Important
After repair or replacement of faulty parts, conduct Clear Memory Mode and Inspection Mode .

WIRING DIAGRAM:

CHECK OPERATING SOUND OF FUEL PUMP.

Make sure that fuel pump is in operation for two seconds when turning the ignition switch to ON.

Note
Fuel pump operation can also be executed using Vehicle Diagnostic Interface.
For the procedure, refer to “Compulsory Valve Operation Check Mode”.

Does the fuel pump produce operating sound?

Yes

Check fuel injector circuit.

CHECK GROUND CIRCUIT OF FUEL PUMP.

Turn the ignition switch to OFF.

Remove the fuel pump access hole lid.

Disconnect the connector from fuel pump.

Measure the resistance of harness connector between fuel pump and chassis ground.

Connector & terminal

(R58) No. 4 — Chassis ground:

Is the resistance less than 5 Ω?

Yes

•

Repair harness and connector.

•

Note
In this case, repair the following:
•	Open circuit in harness between fuel pump connector and chassis grounding terminal
•	Poor contact in coupling connector

CHECK POWER SUPPLY TO FUEL PUMP.

Turn the ignition switch to ON.

Measure the voltage of power supply circuit between fuel pump connector and chassis ground.

Connector & terminal

(R58) No. 1 (+) — Chassis ground (−):

Is the voltage more than 10 V?

Yes

Replace the fuel pump.

CHECK HARNESS BETWEEN FUEL PUMP AND FUEL PUMP RELAY CONNECTOR.

Turn the ignition switch to OFF.

Measure the resistance of harness connector between fuel pump and fuel pump relay.

Connector & terminal

(R58) No. 1 — (B46) No. 4:

Is the resistance less than 1 Ω?

Yes

•

Repair harness and connector.

•

Note
In this case, repair the following:
•	Open circuit in harness between fuel pump connector and chassis grounding terminal
•	Poor contact in coupling connectors

CHECK HARNESS BETWEEN FUEL PUMP AND FUEL PUMP RELAY CONNECTOR.

Measure the resistance of harness between fuel pump and fuel pump relay connector.

Connector & terminal

(R58) No. 1 — Chassis ground:

Is the resistance more than 1 MΩ?

Yes

Repair short circuit in harness between fuel pump and fuel pump relay connector.

CHECK FUEL PUMP RELAY.

Disconnect the connectors from fuel pump relay and main relay.

Remove the fuel pump relay and main relay with bracket.

Connect the battery to fuel pump relay connector terminals No. 1 and No. 3.

Measure the resistance between connector terminals of fuel pump relay.

Terminals

No. 2 — No. 4:

Is the resistance less than 10 Ω?

Yes

Replace the fuel pump relay.

CHECK HARNESS BETWEEN ECM AND FUEL PUMP RELAY CONNECTOR.

Disconnect the connectors from ECM.

Measure the resistance of harness between ECM and fuel pump relay connector.

Connector & terminal

(B135) No. 26 — (B46) No. 3:

Is the resistance less than 1 Ω?

Yes

Repair open circuit in harness between ECM and fuel pump relay connector.

CHECK POOR CONTACT.

Check poor contact in ECM connector.

Is there poor contact in ECM connector?

Yes

Repair poor contact in ECM connector.

Check fuel injector circuit.

FUEL PUMP CIRCUIT

CHECK OPERATING SOUND OF FUEL PUMP.

Does the fuel pump produce operating sound?

CHECK GROUND CIRCUIT OF FUEL PUMP.

Is the resistance less than 5 Ω?

CHECK POWER SUPPLY TO FUEL PUMP.

Is the voltage more than 10 V?

CHECK HARNESS BETWEEN FUEL PUMP AND FUEL PUMP RELAY CONNECTOR.

Is the resistance less than 1 Ω?

CHECK HARNESS BETWEEN FUEL PUMP AND FUEL PUMP RELAY CONNECTOR.

Is the resistance more than 1 MΩ?

CHECK FUEL PUMP RELAY.

Is the resistance less than 10 Ω?

CHECK HARNESS BETWEEN ECM AND FUEL PUMP RELAY CONNECTOR.

Is the resistance less than 1 Ω?

CHECK POOR CONTACT.

Is there poor contact in ECM connector?

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