SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned to ON, battery voltage is applied to the IGSW of the ECM. The output signal from the MREL terminal of the ECM causes a current to flow to the coil, closing the contacts of the integration relay (EFI relay) and supplying power to either terminal +B or +B2 of the ECM.

WIRING DIAGRAM



CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - BATTERY)

    B001ZLJE05
    Text in Illustration
    *a Front view of wire harness connector (to Integration Relay)

    1. Remove the integration relay from the engine room relay block.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1X-1 - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT INTEGRATION RELAY (EFI MAIN NO.1 RELAY AND IG2 MAIN NO.1 RELAY)


    1. Inspect the integration relay Click here.


    NG

    REPLACE INTEGRATION RELAY

    OK

  3. CHECK HARNESS AND CONNECTOR (+B, +B2 AND MREL CIRCUIT)


    1. Check the harness and the connectors between the integration relay and the ECM.


      1. Remove the integration relay from the engine room relay block.

      2. Disconnect the ECM connector.

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

        Standard Resistance
        for Manual Transmission Models
        Tester Connection Condition Specified Condition
        A38-34 (MREL) - 1S-8 Always Below 1 Ω
        A38-3 (+B) - 1S-11 Always Below 1 Ω
        A38-2 (+B2) - 1S-11 Always Below 1 Ω
        A38-34 (MREL) or 1S-8 - Body ground Always 10 kΩ or higher
        A38-3 (+B) or 1S-11 - Body ground Always 10 kΩ or higher
        A38-2 (+B2) or 1S-11 - Body ground Always 10 kΩ or higher
        for Automatic Transmission Models
        Tester Connection Condition Specified Condition
        A38-6 (MREL) - 1S-8 Always Below 1 Ω
        A38-2 (+B) - 1S-11 Always Below 1 Ω
        A38-3 (+B2) - 1S-11 Always Below 1 Ω
        A38-6 (MREL) or 1S-8 - Body ground Always 10 kΩ or higher
        A38-2 (+B) or 1S-11 - Body ground Always 10 kΩ or higher
        A38-3 (+B2) or 1S-11 - Body ground Always 10 kΩ or higher

    2. Check the harness and connectors between the integration relay and body ground.


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

        Standard Resistance
        Tester Connection Condition Specified Condition
        1S-4 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)


    1. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C45-81 (E1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT ECM (IGSW VOLTAGE)

    B001WC1C01
    *A for Manual transmission models
    *B for Automatic transmission models
    *a

    Front view of wire harness connector

    (to ECM)

    1. Disconnect the ECM connector.

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

      Standard Voltage
      for Manual Transmission Models
      Tester Connection Switch Condition Specified Condition
      A38-28 (IGSW) - C45-81 (E1) Ignition switch ON 11 to 14 V
      for Automatic Transmission Models
      Tester Connection Switch Condition Specified Condition
      A38-4 (IGSW) - C45-81 (E1) Ignition switch ON 11 to 14 V

    OK

    REPLACE ECM Click here

    NG

  6. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM, INTEGRATION RELAY - BODY GROUND)


    1. Remove the integration relay from the engine room relay block.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      for Manual Transmission Models
      Tester Connection Condition Specified Condition
      1P-7 - A38-28 (IGSW) Always Below 1 Ω
      1P-7 or A38-28 (IGSW) - Body ground Always 10 kΩ or higher
      for Automatic Transmission Models
      Tester Connection Condition Specified Condition
      1P-7 - A38-4 (IGSW) Always Below 1 Ω
      1P-7 or A38-4 (IGSW) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK IF VEHICLE IS EQUIPPED WITH ENTRY AND START SYSTEM

    Result
    Result Proceed to
    w/ Entry and Start System A
    w/o Entry and Start System B

    B

    CHECK HARNESS AND CONNECTOR (IGNITION SWITCH - ENGINE ROOM RELAY BLOCK) Click here

    A

  8. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ENGINE ROOM RELAY BLOCK


    1. Remove the integration relay from the engine room relay block.

    2. Disconnect the certification ECU (smart key ECU assembly) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E128-3 (IG1D) - 1R-2 Always Below 1 Ω
      E128-3 (IG2D) or 1R-2 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. CHECK ENTRY AND START SYSTEM (POWER SOURCE MODE DOES NOT CHANGE)


    1. Check the entry and start system Click here.


    OK

    REPLACE ECM Click here

    NG

    REPAIR ENTRY AND START SYSTEM Click here

  10. CHECK HARNESS AND CONNECTOR (IGNITION SWITCH - ENGINE ROOM RELAY BLOCK)


    1. Remove the integration relay from the engine room relay block.

    2. Disconnect the ignition switch connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E93-6 (IG2) - 1R-2 Always Below 1 Ω
      E93-6 (IG2) or 1R-2 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. INSPECT IGNITION SWITCH ASSEMBLY


    1. Inspect the ignition switch assembly Click here.


    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION SWITCH - BATTERY)

    NG

    REPLACE IGNITION SWITCH ASSEMBLY Click here