SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

When the engine switch is turned on (IG), 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 contact and supplying power to terminals +B and +B2 of the ECM.

WIRING DIAGRAM

B000M7UE01

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY VOLTAGE)


    1. Disconnect the No. 1 integration relay 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
      1C-8 - Body ground Engine switch on (IG) 11 to 14 V

    NG

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

    OK

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


    1. Disconnect the No. 1 integration relay connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1D-3 - Body ground Always 11 to 14 V
      1B-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. Disconnect the No. 1 integration relay connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1E-2 - 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. Disconnect the No. 1 integration relay 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
      1C-1 - A84-6 (IGSW) Always Below 1 Ω
      1C-9 - A84-2 (+B) Always Below 1 Ω
      1C-10 - A84-3 (+B2) Always Below 1 Ω
      1C-7 - A84-46 (MREL) Always Below 1 Ω
      1C-1 or A84-6 (IGSW) - Body ground and other terminals Always 10 kΩ or higher
      1C-9 or A84-2 (+B) - Body ground and other terminals Always 10 kΩ or higher
      1C-10 or A84-3 (+B2) - Body ground and other terminals Always 10 kΩ or higher
      1C-7 or A84-46 (MREL) - Body ground and other terminals Always 10 kΩ or higher

    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
      E96-53 (E1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

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


    1. Disconnect the No. 1 integration relay connector.

    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
      A43-9 (IG2D) - 1C-8 Always Below 1 Ω
      A43-9 (IG2D) or 1C-8 - Body ground and other terminals Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    GO TO SMART ENTRY AND START SYSTEM Click here