SFI SYSTEM (for Hatchback) > Fuel Pump Control Circuit


DESCRIPTION

When the engine is cranked, the ST (Starter) relay drive signal is input to the STA terminal of the ECM, and NE signal generated by the crankshaft position sensor is also input to the NE+ terminal. Thus, the ECM interprets that the engine has been cranked, and turns the transistor Tr1 in the ECM internal circuit ON. The current flows to the C/OPN (Circuit Opening) relay by turning the Tr1 ON. Then, the fuel pump operates.
While the NE signal is input to the ECM with the engine running, the ECM turns the Tr1 on continuously.

WIRING DIAGRAM


A259671E02


INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
1.PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE FUEL PUMP/SPEED)

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

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

  1. Check whether the fuel pump operating sound occurs when performing the Active Test on the Techstream.

    Result 
    Result
    		Proceed to
    Fuel pump operating sound does not occur
    		A
    Fuel pump operating sound occurs
    		B


B
Go to step 6
A


2.INSPECT NO. 1 INTEGRATION RELAY (C/OPN RELAY)
A257632E01

  1. Remove the No. 1 integration relay.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    1E-4 - 1E-5
    		Battery voltage not applied
    		10 kΩ or higher
    Battery voltage applied to terminals 1D-9 and 1E-11
    		Below 1 Ω
    Text in Illustration 
    *a
    		Component without harness connected
    (No. 1 Integration Relay Bottom View)


NG
REPLACE NO. 1 INTEGRATION RELAY (Click here)
OK


3.CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - ECM)

  1. Remove the No. 1 integration relay.

  1. Disconnect the ECM connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    1E-11 - A72-21 (FC)
    		Always
    		Below 1 Ω
    1E-11 or A72-21 (FC) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - FUEL PUMP - BODY GROUND)

  1. Remove the No. 1 integration relay.

  1. Disconnect the fuel pump connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    1E-5 - J71-4
    		Always
    		Below 1 Ω
    J71-5 - Body ground
    		Always
    		Below 1 Ω
    1E-5 or J71-4 - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.INSPECT FUEL PUMP

  1. Inspect fuel pump (Click here).

    HINT:
    Perform "Inspection After Repair" after replacing the fuel pump (Click here).


NG
REPLACE FUEL PUMP (Click here)
OK

REPLACE ECM (Click here)  

6.READ VALUE USING TECHSTREAM (STARTER SIGNAL)

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

  1. Enter the following menus: Powertrain / Engine and ECT / Data List / Starter Signal.

  1. Check the result when the ignition switch is ON and the engine starts.

    OK:
    Ignition Switch Position
    		Techstream Display
    (Starter Signal)
    ON
    		OFF
    START
    		ON


NG
CHECK STARTER SIGNAL CIRCUIT (Click here)
OK


7.READ VALUE USING TECHSTREAM (ENGINE SPEED)

  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

  1. Enter the following menus: Powertrain / Engine and ECT / Data List / Engine Speed.

  1. Read the values displayed on the Techstream while cranking.

    OK:
    Values are displayed continuously.


NG
CHECK CRANKSHAFT POSITION SENSOR CIRCUIT (Click here)
OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (Click here)