SFI SYSTEM ECM Power Source Circuit

DTC Code DTC Name
ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned to ON, the battery voltage is applied to the IGSW and BATT terminals of the ECM. The output signal from the MREL terminal of the ECM causes a current to flow to the EFI-MAIN relay coil, closing the EFI-MAIN relay contacts and supplying power to terminal +B and +B1 of the ECM.

WIRING DIAGRAM

A326913E01

CAUTION / NOTICE / HINT

Note:

  • After replacing the ECM, perform idle learning.

    Click here

  • Inspection the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

  1. CHECK TERMINAL VOLTAGE (POWER SOURCE OF ECM)

    A326916C01

    *a

    Front view of wire harness connector

    (to ECM)

    1. Disconnect the ECM connector.

    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

      A34-37 (IGSW) - Body ground

      Ignition switch ON

      11 to 14 V

      Result

      Proceed to

      OK

      NG
    NG

    CHECK TERMINAL VOLTAGE (POWER SOURCE OF DRIVER SIDE JUNCTION BLOCK ASSEMBLY)Click here

    OK

  2. CHECK TERMINAL VOLTAGE (POWER SOURCE OF EFI-MAIN RELAY)

    1. A201082C12

      *a

      Front view of wire harness connector

      (to Driver Side Junction Block Assembly)

      Disconnect the driver side junction block assembly connector.

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      3B-1 - Body ground

      Always

      11 to 14 V

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVER SIDE JUNCTION BLOCK ASSEMBLY - BATTERY)

    OK

  3. INSPECT DRIVER SIDE JUNCTION BLOCK ASSEMBLY

    1. Inspect the EFI-MAIN relay.

      1. Remove the driver side junction block assembly.

        Click here

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

        Standard Resistance

        Tester Connection

        Condition

        Specified Condition

        3B-1 - 3C-7

        Battery voltage applied between terminals 3D-14 and 3J-7

        Below 1 Ω

        Battery voltage not applied between terminals 3D-14 and 3J-7

        10 kΩ or higher

      3. Install the driver side junction block assembly.

        Click here

    2. Disconnect the driver side junction block assembly connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      3B-1 - 3P-8

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE DRIVER SIDE JUNCTION BLOCK ASSEMBLY

    Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (DRIVER SIDE JUNCTION BLOCK ASSEMBLY - ECM)

    1. Disconnect the driver side junction block assembly connector.

    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

      A34-9 (MREL) - 3D-14

      Always

      Below 1 Ω

      A34-2 (+B) - 3C-7

      Always

      Below 1 Ω

      A34-1 (+B1) - 3C-7

      Always

      Below 1 Ω

      A34-15 (BATT) - 3P-8

      A34-9 (MREL) or 3D-14 - Body ground

      Always

      10 kΩ or higher

      A34-1 (+B1), A34-2 (+B) or 3C-7 - Body ground

      Always

      10 kΩ or higher

      A34-15 (BATT) or 3P-8 - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (DRIVER SIDE JUNCTION BLOCK ASSEMBLY - BODY GROUND)

    1. Disconnect the driver side junction block assembly connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      3J-7 - Body ground

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    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

      A34-4 (E1) - Body ground

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    Click hereClick here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  7. CHECK TERMINAL VOLTAGE (POWER SOURCE OF DRIVER SIDE JUNCTION BLOCK ASSEMBLY)

    1. Disconnect the driver side junction block assembly connector.

    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

      3N-2 - Body ground

      Ignition switch ON

      11 to 14 V

      Result

      Result

      Proceed to

      OK

      A

      NG (w/ entry and start system)

      B

      NG (w/o entry and start system)

      C
    B

    INSPECT IG2 RELAYClick here

    C

    INSPECT IGNITION OR STARTER SWITCH ASSEMBLYClick here

    A

  8. INSPECT DRIVER SIDE JUNCTION BLOCK ASSEMBLY

    1. Disconnect the driver side junction block assembly connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      3N-2 - 3C-1

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE DRIVER SIDE JUNCTION BLOCK ASSEMBLY

    Click here

    OK

  9. CHECK HARNESS AND CONNECTOR (DRIVER SIDE JUNCTION BLOCK ASSEMBLY - ECM)

    1. Disconnect the driver side junction block assembly connector.

    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

      3C-1 - A34-37 (IGSW)

      Always

      Below 1 Ω

      3C-1 or A34-37 (IGSW) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    Click hereClick here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  10. INSPECT IG2 RELAY

    1. Inspect the IG2 relay.

      Click here

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE IG2 RELAY

    OK

  11. CHECK TERMINAL VOLTAGE (POWER SOURCE OF IG2 RELAY)

    1. Remove the IG2 relay from the center relay block.

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      3 (IG2 relay) - Body ground

      Always

      11 to 14 V

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IG2 RELAY - BATTERY)

    OK

  12. CHECK HARNESS AND CONNECTOR (IG2 RELAY - DRIVER SIDE JUNCTION BLOCK ASSEMBLY)

    1. Remove the IG2 relay from the center relay block.

    2. Disconnect the driver side junction block assembly connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      5 (IG2 relay) - 3N-2

      Always

      Below 1 Ω

      5 (IG2 relay) or 3N-2 - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

    1. Remove the IG2 relay from the center relay block.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      1 (IG2 relay) - Body ground

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  14. CHECK HARNESS AND CONNECTOR (IG2 RELAY - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))

    1. Remove the IG2 relay from the center relay block.

    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

      2 (IG2 relay) - E49-20 (IG1D)

      Always

      Below 1 Ω

      2 (IG2 relay) or E49-20 (IG1D) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

    GO TO ENTRY AND START SYSTEM

    Click hereClick here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  15. INSPECT IGNITION OR STARTER SWITCH ASSEMBLY

    1. Inspect the ignition or starter switch assembly.

      Click here

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE IGNITION OR STARTER SWITCH ASSEMBLY

    Click here

    OK

  16. CHECK HARNESS AND CONNECTOR (IGNITION OR STARTER SWITCH ASSEMBLY - DRIVER SIDE JUNCTION BLOCK ASSEMBLY)

    1. Disconnect the ignition or starter switch assembly connector.

    2. Disconnect the driver side junction block assembly connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      E21-6 (IG2) - 3N-2

      Always

      Below 1 Ω

      E21-6 (IG2) or 3N-2 - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR