SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

When the engine switch is turned on (IG), the battery voltage is applied to 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 EFI-MAIN NO. 1 relay and supplying power to terminal is +B and +B2 of the ECM.

WIRING DIAGRAM

B008J2EE01

CAUTION / NOTICE / HINT

Note

Inspect the fuses for circuits related to this system before performing the following 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
      C65-59 (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)


    1. B008HNOC13
      *a

      Front view of wire harness connected

      (to ECM)

      Disconnect the ECM connector.

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A35-6 (IGSW) - Body ground Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT IG2-MAIN 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 (ECM - EFI-MAIN NO. 1 RELAY)


    1. Disconnect the ECM connector.

    2. Remove the EFI-MAIN NO. 1 relay from the No. 1 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
      A35-46 (MREL) - 1 (EFI-MAIN NO. 1 relay holder) Always Below 1 Ω
      A35-2 (+B) - 3 (EFI-MAIN NO. 1 relay holder) Always Below 1 Ω
      A35-3 (+B2) - 3 (EFI-MAIN NO. 1 relay holder) Always Below 1 Ω
      A35-46 (MREL) or 1 (EFI-MAIN NO. 1 relay holder) - Body ground and other terminals Always 10 kΩ or higher
      A35-2 (+B) or 3 (EFI-MAIN NO. 1 relay holder) - Body ground and other terminals Always 10 kΩ or higher
      A35-3 (+B2) or 3 (EFI-MAIN NO. 1 relay holder) - 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 HARNESS AND CONNECTOR (POWER SOURCE VOLTAGE OF EFI-MAIN NO. 1 RELAY)


    1. B008IV0C01
      *1 No. 1 Engine Room Relay Block and Junction Block Assembly
      *2 EFI-MAIN NO. 1 Relay

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Remove the EFI-MAIN NO. 1 relay from the No. 1 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 (EFI-MAIN NO.1 relay holder) - 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-MAIN RELAY


    1. Inspect the IG2-MAIN relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE IG2-MAIN RELAY

    OK

  8. CHECK HARNESS AND CONNECTOR (ECM - IG2-MAIN RELAY)


    1. Disconnect the ECM connector.

    2. Remove the IG2-MAIN relay from the No. 1 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
      A35-6 (IGSW) - 5 (IG2-MAIN relay holder) Always Below 1 Ω
      A35-6 (IGSW) or 5 (IG2-MAIN relay holder) - 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 HARNESS AND CONNECTOR (POWER SOURCE VOLTAGE OF IG2-MAIN RELAY)


    1. B008JK4C01
      *1 No. 1 Engine Room Relay Block and Junction Block Assembly
      *2 IG2-MAIN Relay

      Remove the IG2-MAIN relay from the No. 1 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 (IG2-MAIN relay holder) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. CHECK HARNESS AND CONNECTOR (IG2-MAIN RELAY - BODY GROUND)


    1. Remove the IG2-MAIN relay from the No. 1 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-MAIN relay holder) - 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 - IG2-MAIN RELAY)


    1. Remove the IG2-MAIN relay from the No. 1 engine room relay block and junction block assembly.

    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
      I51-3 (IG1D) - 1 (IG2-MAIN relay holder) Always Below 1 Ω
      I51-3 (IG1D) or 1 (IG2-MAIN relay holder) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    GO TO SMART ENTRY AND START SYSTEM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR