SFI SYSTEM Fuel Pump Control Circuit

DESCRIPTION

When the engine is cranked, the start request signal output from the power management control ECU is input to the ECM, and the 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 transistor Tr1 in the ECM internal circuit on. Current flows to the C/OPN (Circuit Opening) relay by turning Tr1 on. Then, the fuel pump operates.

While the NE signal is input to the ECM with the engine running, the ECM turns Tr1 on continuously.

WIRING DIAGRAM

A011WDWE02

INSPECTION PROCEDURE

Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

  1. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE FUEL PUMP / SPEED)

    1. Connect the Techstream to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the Techstream on.

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

    5. 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

    READ VALUE USING TECHSTREAM (STARTER SIGNAL) Click here

    A

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

    1. Remove the No. 1 integration relay from the engine room relay block and junction block assembly.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1E-1 - A25-21 (FC) Always Below 1 Ω
      1E-1 or A25-21 (FC) - Body ground Always 10 kΩ or higher
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

    1. Remove the No. 1 integration relay from the engine room relay block and junction block assembly.

    2. Disconnect the fuel pump connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1C-6 - N11-4 (B) Always Below 1 Ω
      1C-6 or N11-4 (B) - Body ground Always 10 kΩ or higher
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (FUEL PUMP - BODY GROUND)

    1. Disconnect the fuel pump connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      N11-5 (E) - Body ground Always Below 1 Ω
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT FUEL PUMP

    1. Inspect the fuel pump Click here.

      Tech Tips

      Perform "Inspection After Repair" after replacing the fuel pump Click here.

    NG

    REPLACE FUEL PUMP Click here

    OK

  6. CHECK TERMINAL VOLTAGE (POWER SOURCE OF NO. 1 INTEGRATION RELAY)

    1. Remove the No. 1 integration relay from the engine room relay block and junction block assembly.

      A011VPBE06

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      1D-1 - Body ground Always 11 to 14 V
      Text in Illustration
      *a

      Front view of wire harness connector

      (to No. 1 Integration Relay)
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - NO. 1 INTEGRATION RELAY)

    OK

    REPLACE NO. 1 INTEGRATION RELAY Click here

  7. READ VALUE USING TECHSTREAM (STARTER SIGNAL)

    1. Connect the Techstream to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the Techstream on.

    4. Put the engine in inspection mode (maintenance mode) Click here.

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

    6. Check the result when the power switch on (IG) and the engine starts.

      OK
      Condition Starter Signal
      Power switch on (IG) Close (OFF)
      Engine started Open (ON)
    NG

    GO TO HYBRID CONTROL SYSTEM Click here

    OK

  8. READ VALUE USING TECHSTREAM (ENGINE SPEED)

    1. Connect the Techstream to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the Techstream on.

    4. Put the engine in inspection mode (maintenance mode) Click here.

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

    6. 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