ECD SYSTEM(w/ DPF) ECM Power Source Circuit

DESCRIPTION

When the engine switch is turned on (IG), the 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, closing the contacts of the integration relay (EFI relay) and supplying power to terminal +B of the ECM.

WIRING DIAGRAM

A01XA8UE01
A01XA8UE02

CAUTION / NOTICE / HINT

Note

After replacing the ECM, the new ECM needs registration (See page ) and initialization Click here.

PROCEDURE


  1. INSPECT INTEGRATION RELAY (INTEGRATION RELAY - BODY GROUND)

    A01X7YTE01
    *a Front view of wire harness connector: (to Engine Room Relay Block)
    *b Integration Relay

    1. Remove the 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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT INTEGRATION RELAY (EFI RELAY AND IG2 RELAY)

    A01X46SE01

    1. Remove the integration relay from the engine room relay block.

    2. Inspect the EFI MAIN fuse and the IG2 MAIN fuse.


      1. Remove the EFI MAIN fuse and IG2 MAIN fuse from the integration relay.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        EFI MAIN fuse Always Below 1 Ω
        IG2 MAIN fuse Always Below 1 Ω

    3. Inspect the EFI relay and the IG2 relay.


      1. 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 to terminals 1B-2 and 1B-3 10 kΩ or higher
        Battery voltage applied to terminals 1B-2 and 1B-3 Below 1 Ω
        1C-1 - 1B-8 Battery voltage not applied to terminals 1B-7 and 1B-6 10 kΩ or higher
        Battery voltage applied to terminals 1B-7 and 1B-6 Below 1 Ω

    NG

    REPLACE INTEGRATION RELAY

    OK

  3. CHECK HARNESS AND CONNECTOR (+B AND MREL CIRCUIT)

    A01X8SHE01

    1. Check the harness and the connectors between the integration relay and the ECM.


      1. Remove the integration relay from the engine room relay block.

      2. Disconnect the ECM connector.

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

        Standard Resistance
        for LHD
        Tester Connection Condition Specified Condition
        A38-44 (MREL) - 1B-2 Always Below 1 Ω
        A38-2 (+B) - 1B-4 Always Below 1 Ω
        A38-1 (+B2) - 1B-4 Always Below 1 Ω
        A38-44 (MREL) or 1B-2 - Body ground Always 10 kΩ or higher
        A38-2 (+B) or 1B-4 - Body ground Always 10 kΩ or higher
        A38-1 (+B2) or 1B-4 - Body ground Always 10 kΩ or higher
        for RHD
        Tester Connection Condition Specified Condition
        A52-44 (MREL) - 1B-2 Always Below 1 Ω
        A52-2 (+B) - 1B-4 Always Below 1 Ω
        A52-1 (+B2) - 1B-4 Always Below 1 Ω
        A52-44 (MREL) or 1B-2 - Body ground Always 10 kΩ or higher
        A52-2 (+B) or 1B-4 - Body ground Always 10 kΩ or higher
        A52-1 (+B2) or 1B-4 - Body ground Always 10 kΩ or higher

    2. Check the harness and connectors between the integration relay and body ground.


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

        Standard Resistance
        Tester Connection Condition Specified Condition
        1B-3 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

    A01X71BE01

    1. Disconnect the ECM connector.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      C45-81 (E1) - Body ground Always Below 1 Ω
      for RHD
      Tester Connection Condition Specified Condition
      C46-81 (E1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT ECM (IGSW VOLTAGE)

    A01X57OE01

    1. Disconnect the ECM connectors.

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      for LHD
      Tester Connection Switch Condition Specified Condition
      A38-28 (IGSW) - C45-81 (E1) Engine switch on (IG) 11 to 14 V
      for RHD
      Tester Connection Switch Condition Specified Condition
      A52-28 (IGSW) - C46-81 (E1) Engine switch on (IG) 11 to 14 V

    OK

    REPLACE ECM Click here

    NG

  6. INSPECT FUSE (IGN)

    A01XB2WE03
    *1 Engine Room Relay Block:

    1. Remove the IGN fuse from the engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      IGN fuse Always Below 1 Ω

    NG

    CHECK FOR SHORT IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE

    OK

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

    A01X8SHE02

    1. Remove the integration relay from the engine room relay block.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      1B-8 - A38-28 (IGSW) Always Below 1 Ω
      1B-8 or A38-28 (IGSW) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      1B-8 - A52-28 (IGSW) Always Below 1 Ω
      1B-8 or A52-28 (IGSW) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - ENGINE ROOM RELAY BLOCK)

    A01X927E01
    *1 Front view of wire harness connector: (to Main Body ECU)
    *2 Front view of wire harness connector: (to Engine Room Relay Block)
    *3 Integration Relay

    1. Remove the integration relay from the engine room relay block.

    2. Disconnect the E2 main body ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E2-11 (IG2D) - 1B-6 Always Below 1 Ω
      E2-11 (IG2D) or 1B-6 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. CHECK ENTRY AND START SYSTEM (POWER SOURCE MODE DOES NOT CHANGE)


    1. Check the entry and start system Click here.


    OK

    REPLACE ECM Click here

    NG

    REPAIR ENTRY AND START SYSTEM