SFI SYSTEM > Fuel Pump Control Circuit

for Preparation Click here


DESCRIPTION

When the engine is cranked, current flows from terminal ST2 of the ignition switch to the starter relay (Marking: ST) coil, and current also flows to terminal STA of the ECM (STA signal).
When the STA signal and NE signal are transmitted to the ECM, the power transistor (Tr) is turned ON, current flows to the circuit opening relay (Marking: C/OPN) coil, the relay switches on, power is supplied to the fuel pump and the fuel pump operates.
While the NE signal is generated (when engine running), the ECM keeps Tr ON (circuit opening relay ON) and the fuel pump also keeps operating.

A113512E01


WIRING DIAGRAM


G037761E02


INSPECTION PROCEDURE


When using intelligent tester:

1.PERFORM ACTIVE TEST (OPERATE C/OPN RELAY)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch ON and turn the intelligent tester ON.

  1. Enter the following menus: Powertrain / Engine and ECT / Active Test / Fuel Pump.

  1. Check the operation of the relay while operating it using the intelligent tester.

    OK:
    Operating noise can be heard from the fuel pump.



OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
NG


2.CHECK ECM POWER SOURCE CIRCUIT

  1. Refer to ECM power source circuit (Click here).



NG
REPAIR OR REPLACE POWER SOURCE CIRCUIT
OK


3.CHECK ECM (FC VOLTAGE)
A066060E23

  1. Turn the ignition switch ON.

  1. Measure the voltage of the ECM connectors.

    Standard voltage:
    Tester Connection
    		Specified Condition
    E9-25 (FC) - E12-3 (E1)
    		9 to 14 V



OK
Go to step 6
NG


4.CHECK INTEGRATION RELAY (C/OPN RELAY)
G039047E03

  1. Remove the integration relay from the engine room junction block (Click here).

  1. Measure the voltage of the C/OPN relay.

    Standard voltage:
    Terminal Connection
    		Condition
    		Specified Condition
    1J-8 - Body ground
    		Ignition switch ON
    		10 to 14 V



NG
REPLACE INTEGRATION RELAY
OK


5.CHECK WIRE HARNESS (C/OPN RELAY - ECM)
G034949E02

  1. Disconnect the 1J integration relay connector from the engine room junction block (Click here).

  1. Disconnect the E9 ECM connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    1J-2 - E9-8 (MREL)
    		Below 1 Ω
    1J-7 - E9-25 (FC)
    		Below 1 Ω
    1J-2 or E9-8 (MREL) - Body ground
    		10 kΩ or higher
    1J-7 or E9-25 (FC) - Body ground
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

REPLACE ECM 

6.INSPECT FUEL PUMP

  1. Inspect the fuel pump (Click here).



NG
REPAIR OR REPLACE FUEL PUMP
OK


7.CHECK WIRE HARNESS (C/OPN RELAY - FUEL PUMP, FUEL PUMP - BODY GROUND)
G034951E01

  1. Disconnect the 1J integration relay connector from the engine room junction block (Click here).

  1. Disconnect the F15 fuel pump connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    1J-8 - F15-4
    		Below 1 Ω
    F15-5 - Body ground
    		Below 1 Ω
    1J-8 or F15-4 - Body ground
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

REPLACE ECM 


When not using intelligent tester:

1.INSPECT OPERATION OF FUEL PUMP

  1. Operation of fuel pump (Click here).



OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
NG


2.CHECK ECM POWER SOURCE CIRCUIT

  1. Refer to ECM power source circuit (Click here).



NG
REPAIR OR REPLACE POWER SOURCE CIRCUIT
OK


3.CHECK ECM (FC VOLTAGE)
A066060E23

  1. Turn the ignition switch ON.

  1. Measure the voltage of the ECM connectors.

    Standard voltage:
    Tester Connection
    		Specified Condition
    E9-25 (FC) - E12-3 (E1)
    		9 to 14 V



OK
Go to step 6
NG


4.CHECK INTEGRATION RELAY (C/OPN RELAY)
G039047E03

  1. Remove the integration relay from the engine room junction block (Click here).

  1. Measure the voltage of the C/OPN relay.

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    1J-8 - Body ground
    		Ignition switch ON
    		10 to 14 V



NG
REPLACE INTEGRATION RELAY
OK


5.CHECK WIRE HARNESS (C/OPN RELAY - ECM)
G034949E02

  1. Disconnect the 1J integration relay connector from the engine room junction block (Click here).

  1. Disconnect the E9 ECM connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    1J-2 - E9-8 (MREL)
    		Below 1 Ω
    1J-7 - E9-25 (FC)
    		Below 1 Ω
    1J-2 or E9-8 (MREL) - Body ground
    		10 kΩ or higher
    1J-7 or E9-25 (FC) - Body ground
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

REPLACE ECM 

6.INSPECT FUEL PUMP

  1. Inspect the fuel pump (Click here).



NG
REPAIR OR REPLACE FUEL PUMP
OK


7.CHECK WIRE HARNESS (C/OPN RELAY - FUEL PUMP, FUEL PUMP - BODY GROUND)
G034951E01

  1. Disconnect the 1J integration relay connector from the engine room junction block (Click here).

  1. Disconnect the F15 fuel pump connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    1J-8 - F15-4
    		Below 1 Ω
    F15-5 - Body ground
    		Below 1 Ω
    1J-8 or F15-4 - Body ground
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

REPLACE ECM