СИСТЕМА SFI 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 EFI MAIN relay coil, closing the EFI MAIN relay contacts and supplying power to terminal +B of the ECM.

WIRING DIAGRAM

A00DRAPE02

INSPECTION PROCEDURE

Note

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

PROCEDURE

  1. INSPECT INTEGRATION NO.1 RELAY (POWER SOURCE)

    A00DR35E01

    1. Remove the integration relay from the engine room No. 1 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
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Integration Relay)
      *2 Engine Room No. 1 Relay Block

    3. Reinstall the integration relay.

    NG

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

    OK

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

    A00DQBCE01

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

    2. 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 not applied 10 kΩ or higher
      Battery voltage applied to terminals 1B-3 and 1B-2 Below 1 Ω
      1C-1 - 1A-4 Battery voltage not applied 10 kΩ or higher
      Battery voltage applied to terminals 1A-3 and 1A-2 Below 1 Ω
      Text in Illustration
      *1

      Component without harness connected

      (to Integration Relay)
      *2 Fuse Side
      *3 Connector Side

    3. Reinstall the integration relay.

    NG

    REPLACE INTEGRATION NO.1 RELAY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM, BODY GROUND)

    A00DU3QE01

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

    2. Disconnect the A40 ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      A40-44 (MREL) - 1B-3 Always Below 1 Ω
      A40-2 (+B) - 1B-4 Always Below 1 Ω
      1B-2 - Body ground Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A40-44 (MREL) or 1B-3 - Body ground Always 10 kΩ or higher
      A40-2 (+B) or 1B-4 - Body ground Always 10 kΩ or higher
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Integration Relay)
      *2 Engine Room No. 1 Relay Block
      *3

      Front view of wire harness connector

      (to ECM)

    4. Reinstall the integration relay.

    5. Reconnect the ECM connector.

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)

    A00DSU5E16

    1. Disconnect the B39 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B39-104 (E1) - Body ground Always Below 1 Ω
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ECM)

    3. Reconnect the ECM connector.

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT ECM (IGSW TERMINAL VOLTAGE)

    A00DQDME03

    1. Disconnect the A40 and B39 ECM connectors.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A40-28 (IGSW) - B39-104 (E1) Engine switch on (IG) 11 to 14 V
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ECM)

    3. Reconnect the ECM connectors.

    NG

    CHECK HARNESS AND CONNECTOR (ECM - INTEGRATION RELAY) Click here

    OK

    REPLACE ECM Click here

  6. CHECK HARNESS AND CONNECTOR (ECM - INTEGRATION RELAY)

    A00DU3QE02

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

    2. Disconnect the A40 ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      A40-28 (IGSW) - 1A-4 Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A40-28 (IGSW) or 1A-4 - Body ground Always 10 kΩ or higher
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Integration Relay)
      *2 Engine Room No. 1 Relay Block
      *3

      Front view of wire harness connector

      (to ECM)

    4. Reinstall the integration relay.

    5. Reconnect the ECM connector.

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - POWER MANAGEMENT CONTROL ECU, BODY GROUND)

    A00DS25E01

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

    2. Disconnect the D76 power management control ECU 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 - D76-8 (IG2D) Always Below 1 Ω
      1A-2 - Body ground Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      1A-3 or D76-8 (IG2D) - Body ground Always 10 kΩ or higher
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Integration Relay)
      *2 Engine Room No. 1 Relay Block
      *3

      Front view of wire harness connector

      (to Power Management Control ECU)

    4. Reinstall the integration relay.

    5. Reconnect the power management control ECU connector.

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    CHECK ENTRY AND START SYSTEM Click here