SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned to ON, battery voltage is applied to the IGSW terminal of the ECM. The output signal from the MREL terminal of the ECM causes current to flow to the coil of the No. 1 integration relay (EFI MAIN relay), closing the contacts and supplying power to terminals +B and +B2 of the ECM.

WIRING DIAGRAM

A005MBAE01

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 (NO. 1 INTEGRATION RELAY VOLTAGE)


    1. A005LXLE02
      *a

      Front view of wire harness connector

      (to No. 1 Integration Relay)

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

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1D-17 - Body ground Ignition switch ON 11 to 14 V
      Result
      Result Proceed to
      OK A
      NG (w/o Smart Entry and Start System) B
      NG (w/ Smart Entry and Start System) C

    B

    CHECK HARNESS AND CONNECTOR (BATTERY - IGNITION OR STARTER SWITCH ASSEMBLY) Click here

    C

    CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - NO. 1 INTEGRATION RELAY) Click here

    A

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


    1. A005J42E02
      *a

      Front view of wire harness connector

      (to No. 1 Integration Relay)

      Remove the No. 1 integration 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
      1C-1 - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Inspect the No. 1 integration relay (EFI MAIN and IG2 relay) Click here.


    NG

    REPLACE NO. 1 INTEGRATION RELAY Click here

    OK

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


    1. Remove the No. 1 integration 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
      1E-10 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


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

    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
      1D-9 - A58-37 (IGSW) Always Below 1 Ω
      1E-4 - A58-2 (+B) Always Below 1 Ω
      1E-4 - A58-3 (+B2) Always Below 1 Ω
      1D-7 - A58-46 (MREL) Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. 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
      B23-16 (E1) - Body ground Always Below 1 Ω

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  7. CHECK HARNESS AND CONNECTOR (BATTERY - IGNITION OR STARTER SWITCH ASSEMBLY)


    1. A005H91E01
      *a

      Front view of wire harness connector

      (to Ignition or Starter Switch Assembly)

      Disconnect the ignition or starter switch assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      F13-5 (AM2) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. INSPECT IGNITION OR STARTER SWITCH ASSEMBLY


    1. Inspect the ignition or starter switch assembly Click here.


    OK

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

    NG

    REPLACE IGNITION OR STARTER SWITCH ASSEMBLY Click here

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


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

    2. Remove the No. 1 integration 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
      F65-9 (IG2D) - 1D-17 Always Below 1 Ω

    OK

    GO TO SMART ENTRY AND START SYSTEM (for Start Function)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR