SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

When the engine switch is turned on (IG), 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 EFI-MAIN NO. 1 relay, closing the contacts and supplying power to terminals +B and +B2 of the ECM.

WIRING DIAGRAM

B007138E02

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
      C96-53 (E1) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK TERMINAL VOLTAGE (IGSW TERMINAL VOLTAGE)


    1. B0071U0C13
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A23-4 (IGSW) - Body ground Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT IG2 NO. 1 RELAY Click here

    OK

  3. INSPECT EFI-MAIN NO. 1 RELAY


    1. Inspect the EFI-MAIN NO. 1 relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE EFI-MAIN NO. 1 RELAY

    OK

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


    1. Disconnect the ECM connector.

    2. Remove the EFI-MAIN NO. 1 relay from the engine room relay block and junction block assembly.

      Tech Tips

      Remove the EFI-MAIN NO. 2 and EFI-MAIN NO. 3 relays connected between the checked terminals as the coil inside the relay influences the measurement value.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 (EFI-MAIN NO. 1 relay) - A23-46 (MREL) Always Below 1 Ω
      5 (EFI-MAIN NO. 1 relay) - A23-2 (+B) Always Below 1 Ω
      5 (EFI-MAIN NO. 1 relay) - A23-3 (+B2) Always Below 1 Ω
      2 (EFI-MAIN NO. 1 relay) or A23-46 (MREL) - Body ground and other terminals Always 10 kΩ or higher
      5 (EFI-MAIN NO. 1 relay) or A23-2 (+B) - Body ground and other terminals Always 10 kΩ or higher
      5 (EFI-MAIN NO. 1 relay) or A23-3 (+B2) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK TERMINAL VOLTAGE (POWER SOURCE OF EFI-MAIN NO. 1 RELAY)

    B006YC9C03
    *1 Engine Room Relay Block and Junction Block Assembly
    *2 EFI-MAIN NO. 1 Relay

    1. Remove the EFI-MAIN NO. 1 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
      3 (EFI-MAIN NO. 1 relay) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

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


    1. Remove the EFI-MAIN NO. 1 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
      1 (EFI-MAIN NO. 1 relay) - Body ground Always Below 1 Ω
      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

  7. INSPECT IG2 NO. 1 RELAY


    1. Inspect the IG2 NO. 1 relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE IG2 NO. 1 RELAY

    OK

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


    1. Disconnect the ECM connector.

    2. Remove the IG2 NO. 1 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
      3 (IG2 NO. 1 relay) - A23-4 (IGSW) Always Below 1 Ω
      3 (IG2 NO. 1 relay) or A23-4 (IGSW) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. CHECK TERMINAL VOLTAGE (POWER SOURCE OF IG2 NO. 1 RELAY)

    B00707EC03
    *1 Engine Room Relay Block and Junction Block Assembly
    *2 IG2 NO. 1 Relay

    1. Remove the IG2 NO. 1 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
      5 (IG2 NO. 1 relay) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

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


    1. Remove the IG2 NO. 1 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
      2 (IG2 NO. 1 relay) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - IG2 NO. 1 RELAY)


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

    2. Remove the IG2 NO. 1 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
      K62-17 (IG1D) - 1 (IG2 NO. 1 relay) Always Below 1 Ω
      K62-17 (IG1D) or 1 (IG2 NO. 1 relay) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    CHECK SMART ENTRY AND START SYSTEM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR