SFI SYSTEM Fuel Injector Circuit

DESCRIPTION

The fuel injector assemblies are located on the intake port. They inject fuel into the cylinders based on the signals from the ECM.

WIRING DIAGRAM

A01SBQWE02

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CHECK TERMINAL VOLTAGE (POWER SOURCE OF FUEL INJECTOR ASSEMBLY)


    1. B0028BUC55
      *a

      Front view of wire harness connector

      (to Fuel Injector Assembly)

      Disconnect the fuel injector assembly connectors.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      C18-1 - Body ground Ignition switch ON 11 to 14 V
      C19-1 - Body ground Ignition switch ON 11 to 14 V
      C20-1 - Body ground Ignition switch ON 11 to 14 V
      C21-1 - Body ground Ignition switch ON 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (INJ RELAY - FUEL INJECTOR ASSEMBLY) Click here

    OK

  2. INSPECT FUEL INJECTOR ASSEMBLY (INJECTION AND VOLUME)


    1. Check the fuel injector assembly injection and volume.

      Click here

      Tech Tips

      Perform "Inspection After Repair" after replacing the fuel injector assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FUEL INJECTOR ASSEMBLY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (FUEL INJECTOR ASSEMBLY - ECM)


    1. Disconnect the ECM connector.

    2. Disconnect the fuel injector assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C18-2 - C53-4 (#10) Always Below 1 Ω
      C19-2 - C53-3 (#20) Always Below 1 Ω
      C20-2 - C53-2 (#30) Always Below 1 Ω
      C21-2 - C53-1 (#40) Always Below 1 Ω
      C18-2 or C53-4 (#10) - Body ground Always 10 kΩ or higher
      C19-2 or C53-3 (#20) - Body ground Always 10 kΩ or higher
      C20-2 or C53-2 (#30) - Body ground Always 10 kΩ or higher
      C21-2 or C53-1 (#40) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  4. CHECK HARNESS AND CONNECTOR (INJ RELAY - FUEL INJECTOR ASSEMBLY)


    1. Disconnect the fuel injector assembly connector.

    2. Remove the INJ relay from the engine room relay block and junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C18-1 - INJ relay terminal 3 Always Below 1 Ω
      C19-1 - INJ relay terminal 3 Always Below 1 Ω
      C20-1 - INJ relay terminal 3 Always Below 1 Ω
      C21-1 - INJ relay terminal 3 Always Below 1 Ω
      C18-1, C19-1, C20-1, C21-1 or INJ relay terminal 3 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT INJ RELAY


    1. Inspect the INJ relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE INJ RELAY

    OK

  6. CHECK TERMINAL VOLTAGE (POWER SOURCE OF INJ RELAY)

    A01SANGC01
    *1 Engine Room Relay Block Assembly
    *2 INJ Relay

    1. Remove the INJ relay from the engine room relay block and junction block assembly.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      INJ relay terminal 5 - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK HARNESS AND CONNECTOR (INJ RELAY - BODY GROUND)


    1. Remove the INJ relay from the engine room relay block and junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      INJ relay terminal 1 - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK HARNESS AND CONNECTOR (INJ RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)


    1. Remove the INJ relay from the engine room relay block and junction block assembly.

    2. Disconnect the instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      INJ relay terminal 2 - 2K-4 Always Below 1 Ω
      INJ relay terminal 2 or 2K-4 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    GO TO ECM POWER SOURCE CIRCUIT Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR