SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

When the power switch is turned on (IG), 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 No. 2 integration relay (EFI MAIN relay) and supplying power to either terminal +B and +B2 of the ECM.

WIRING DIAGRAM

A003TYBE05

INSPECTION PROCEDURE

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 (Check for Open)
      Tester Connection Condition Specified Condition
      B31-104 (E1) - Body ground Always Below 1 Ω

    3. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - BODY GROUND)

    OK

  2. INSPECT ECM (IGSW VOLTAGE)


    1. A003RZJE51
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

    2. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A50-28 (IGSW) - Body ground Power switch on (IG) 11 to 14 V

    4. Reconnect the ECM connector.


    NG

    INSPECT NO. 2 INTEGRATION RELAY (IG2 RELAY) Click here

    OK

  3. INSPECT NO. 2 INTEGRATION RELAY (EFI MAIN RELAY)


    1. A003RV8E17
      Text in Illustration
      *a

      Component without harness connected

      (No. 2 Integration Relay)

      Remove the No. 2 integration relay from the engine room relay block.

    2. Disconnect the No. 2 integration relay connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1C-1 - 1B-4 Battery voltage is not applied between terminals 1B-2 and 1B-3 10 kΩ or higher
      Battery voltage is applied between terminals 1B-2 and 1B-3 Below 1 Ω

    4. Reconnect the No. 2 integration relay connector.

    5. Reinstall the No. 2 integration relay.


    NG

    REPLACE NO. 2 INTEGRATION RELAY Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (EFI MAIN RELAY) - ECM)


    1. Remove the No. 2 integration relay from the engine room relay block.

    2. Disconnect the No. 2 integration relay connector.

    3. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      1B-4 - A50-1 (+B2) Always Below 1 Ω
      1B-4 - A50-2 (+B) Always Below 1 Ω
      1B-2 - A50-6 (MREL) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      1B-4 or A50-1 (+B2) - Body ground Always 10 kΩ or higher
      1B-4 or A50-2 (+B) - Body ground Always 10 kΩ or higher
      1B-2 or A50-6 (MREL) - Body ground Always 10 kΩ or higher

    5. Reconnect the ECM connector.

    6. Reconnect the No. 2 integration relay connector.

    7. Reinstall the No. 2 integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 2 INTEGRATION RELAY (EFI MAIN RELAY) - ECM)

    OK

  5. CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (EFI MAIN RELAY) - BODY GROUND)


    1. Remove the No. 2 integration relay from the engine room relay block.

    2. Disconnect the No. 2 integration relay connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      1B-3 - Body ground Always Below 1 Ω

    4. Reconnect the No. 2 integration relay connector.

    5. Reinstall the No. 2 integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 2 INTEGRATION RELAY (EFI MAIN RELAY) - BODY GROUND)

    OK

  6. CHECK NO. 2 INTEGRATION RELAY (POWER SOURCE VOLTAGE)


    1. A003UT7E01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to No. 2 Integration Relay)

      Remove the No. 2 integration relay from the engine room relay block.

    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

    3. Reconnect the No. 2 integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 2 INTEGRATION RELAY - BATTERY)

    OK

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

  7. INSPECT NO. 2 INTEGRATION RELAY (IG2 RELAY)


    1. A003RV8E18
      Text in Illustration
      *a

      Component without harness connected

      (No. 2 Integration Relay)

      Remove the No. 2 integration relay from the engine room relay block.

    2. Disconnect the No. 2 integration relay connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1C-1 - 1A-4 Battery voltage is not applied to terminals 1A-2 and 1A-3 10 kΩ or higher
      Battery voltage is applied to terminals 1A-2 and 1A-3 Below 1 Ω

    4. Reconnect the No. 2 integration relay connector.

    5. Reinstall the No. 2 integration relay.


    NG

    REPLACE NO. 2 INTEGRATION RELAY Click here

    OK

  8. CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (IG2 RELAY) - ECM)


    1. Disconnect the ECM connector.

    2. Remove the No. 2 integration relay from the engine room relay block.

    3. Disconnect the No. 2 integration relay connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      1A-4 - A50-28 (IGSW) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      1A-4 or A50-28 (IGSW) - Body ground Always 10 kΩ or higher

    5. Reconnect the ECM connector.

    6. Reconnect the No. 2 integration relay connector.

    7. Reinstall the No. 2 integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 2 INTEGRATION RELAY (IG2 RELAY) - ECM)

    OK

  9. CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (IG2 RELAY) - BATTERY)


    1. A003UT7E01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to No. 2 Integration Relay)

      Remove the No. 2 integration relay from the engine room relay block.

    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

    3. Reconnect the No. 2 integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 2 INTEGRATION RELAY - BATTERY)

    OK

  10. CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (IG2 RELAY) - BODY GROUND)


    1. Remove the No. 2 integration relay from the engine room relay block.

    2. Disconnect the No. 2 integration relay connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      1A-3 - Body ground Always Below 1 Ω

    4. Reconnect the No. 2 integration relay connector.

    5. Reinstall the No. 2 integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 2 INTEGRATION RELAY (IG2 RELAY) - BODY GROUND)

    OK

  11. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - NO. 2 INTEGRATION RELAY)


    1. Remove the No. 2 integration relay from the engine room relay block.

    2. Disconnect the No. 2 integration relay connector.

    3. Disconnect the power management control ECU connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      A99-2 (IG2D) - 1A-2 Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A99-2 (IG2D) or 1A-2 - Body ground Always 10 kΩ or higher

    5. Reconnect the No. 2 integration relay connector.

    6. Reinstall the No. 2 integration relay.

    7. Reconnect the power management control ECU connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - NO. 2 INTEGRATION RELAY)

    OK

    CHECK ENTRY AND START SYSTEM Click here