SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

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

WIRING DIAGRAM

B001EIHE02

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 (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
      C153-3 (E1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - BODY GROUND)

    OK

  2. INSPECT ECM (IGSW VOLTAGE)

    B001CN5E02
    Text in Illustration
    *a

    Rear view of wire harness connector

    (to ECM)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G180-8 (IGSW) - Body ground Ignition switch ON 11 to 14 V

    NG

    INSPECT NO. 1 INTEGRATION RELAY (IG2 RELAY) Click here

    OK

  3. INSPECT NO. 1 INTEGRATION RELAY (EFI RELAY)


    1. Inspect the NO. 1 integration relay (EFI relay) Click here.


    NG

    REPLACE NO. 1 INTEGRATION RELAY (EFI RELAY)

    OK

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


    1. Remove the NO. 1 integration relay (EFI 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
      Tester Connection Condition Specified Condition
      1B-4 - G180-1 (+B) Always Below 1 Ω
      1B-4 - G180-2 (+B2) Always Below 1 Ω
      1B-4 or G180-1 (+B) - Body ground Always 10 kΩ or higher
      1B-4 or G180-2 (+B2) - Body ground Always 10 kΩ or higher

    NG

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

    OK

  5. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (EFI RELAY) - BATTERY)


    1. Remove the NO. 1 integration relay (EFI relay) from the engine room relay block.

    2. Disconnect the cable from the negative (-) battery terminal.

    3. Disconnect the cable from the positive (+) battery terminal.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1C-1 - Positive battery terminal Always Below 1 Ω
      1C-1 or Positive battery terminal - Body ground Always 10 kΩ or higher

    NG

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

    OK

  6. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (EFI RELAY) - BODY GROUND)


    1. Remove the NO. 1 integration relay (EFI relay) from the engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1B-3 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 1 INTEGRATION RELAY (EFI RELAY) - BODY GROUND)

    OK

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


    1. Disconnect the ECM connector.

    2. Remove the integration relay (EFI relay) from the engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1B-2 - G181-6 (MREL) Always Below 1 Ω
      1B-2 or G181-6 (MREL) - Body ground Always 10 kΩ or higher

    OK

    REPLACE ECM Click here

    NG

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

  8. INSPECT NO. 1 INTEGRATION RELAY (IG2 RELAY)


    1. Inspect the NO. 1 integration relay (IG2 relay) Click here.


    NG

    REPLACE NO. 1 INTEGRATION RELAY (IG2 RELAY)

    OK

  9. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (IG2 RELAY) - ECM)


    1. Disconnect the ECM connector.

    2. Remove the NO. 1 integration relay (IG2 relay) from the engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1A-5 - G180-8 (IGSW) Always Below 1 Ω
      1A-5 or G180-8 (IGSW) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 1 INTEGRATION RELAY (IG2 RELAY) - ECM)

    OK

  10. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (IG2 RELAY) - BATTERY)


    1. Remove the NO. 1 integration relay (IG2 relay) from the engine room relay block.

    2. Disconnect the cable from the negative (-) battery terminal.

    3. Disconnect the cable from the positive (+) battery terminal.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1C-1 - Positive battery terminal Always Below 1 Ω
      1C-1 or Positive battery terminal - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 1 INTEGRATION RELAY (IG2 RELAY) - BATTERY)

    OK

  11. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (IG2 RELAY) - BODY GROUND)


    1. Remove the NO. 1 integration relay (IG2 relay) from the engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1A-3 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 1 INTEGRATION RELAY (IG2 RELAY) - BODY GROUND)

    OK

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


    1. Confirm the 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 (NO. 1 INTEGRATION RELAY (IG2 RELAY) - IGNITION SWITCH) Click here

    A

  13. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - NO. 1 INTEGRATION RELAY)


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

    2. Disconnect the power management control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G50-8 (IG2D) - 1A-1 Always Below 1 Ω
      G50-8 (IG2D) or 1A-1 - Body ground Always 10 kΩ or higher

    OK

    CHECK ENTRY AND START SYSTEM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - NO. 1 INTEGRATION RELAY)

  14. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (IG2 RELAY) - IGNITION SWITCH)


    1. Disconnect the ignition switch connector.

    2. Remove the NO. 1 integration relay (IG2 relay) from the engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1A-1 - G2-6 (IG2) Always Below 1 Ω
      1A-1 or G2-6 (IG2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 1 INTEGRATION RELAY (IG2 RELAY) - IGNITION SWITCH)

    OK

  15. 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