СИСТЕМА SFI ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned to ON, the battery voltage is applied to the IGSW terminal of the ECM. The output signal from the MREL terminal of the ECM causes a current to flow to the coil of the No. 1 integration relay (MAIN relay), closing the contacts and supplying power to terminals +B of the ECM.

WIRING DIAGRAM

A01BG9FE01

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. CHECK NO. 1 INTEGRATION RELAY (POWER SOURCE)

    A01BCZNE08
    Text in Illustration
    *a

    Front view of wire harness connector

    (to No. 1 Integration Relay)

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

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

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

    NG

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

    OK

  2. INSPECT NO. 1 INTEGRATION RELAY (MAIN)


    1. Inspect the No. 1 integration relay (MAIN) Click here.


    NG

    REPLACE NO. 1 INTEGRATION RELAY

    OK

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


    1. Check the harness and connectors between the No. 1 integration relay and ECM.


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

      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
        B9-8 (MREL) - 1J-2 Always Below 1 Ω
        B9-1 (+B) - 1J-4 Always Below 1 Ω
        B9-8 (MREL) or 1J-2 - Body ground Always 10 kΩ or higher
        B9-1 (+B) or 1J-4 - Body ground Always 10 kΩ or higher

    2. Check the harness and connectors between the No. 1 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
        1J-3 - 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
      D1-3 (E1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT ECM (IGSW VOLTAGE)

    A01BHQUE05
    Text in Illustration
    *a

    Rear view of wire harness connector

    (to ECM)

    1. Disconnect the ECM 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
      B9-9 (IGSW) - D1-3 (E1) Ignition switch ON 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (ECM - IGNITION SWITCH ASSEMBLY) Click here

    OK

    REPLACE ECM Click here

  6. CHECK HARNESS AND CONNECTOR (ECM - IGNITION SWITCH ASSEMBLY)


    1. Disconnect the ECM connector.

    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
      H25-6 (IG2) - B9-9 (IGSW) Always Below 1 Ω
      H25-6 (IG2) or B9-9 (IGSW) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. INSPECT IGNITION SWITCH ASSEMBLY


    1. Inspect the ignition switch assembly.


    NG

    REPLACE IGNITION SWITCH ASSEMBLY

    OK

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