ECD SYSTEM(w/o 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

A01WRWME02

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. INSPECT INTEGRATION RELAY (POWER SOURCE)

    A01WTXF
    *a

    Front view of wire harness connector

    (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
      1M-1 - Body ground Always 11 to 14 V

    NG
    OK
  2. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - BODY GROUND)


    1. Remove the integration relay 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
      1Q-4 - Body ground Always Below 1 Ω

    NG
    OK
  3. INSPECT INTEGRATION RELAY (EFI MAIN NO. 1 AND IG2 MAIN)


    1. Inspect the integration relay Click here.


    NG
    OK
  4. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - 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
      Tester Connection Condition Specified Condition
      A85-44 (MREL) - 1Q-8 Always Below 1 Ω
      A85-2 (+B) - 1Q-11 Always Below 1 Ω
      A85-1 (+B2) - 1Q-11 Always Below 1 Ω
      A85-44 (MREL) or 1Q-8 - Body ground Always 10 kΩ or higher
      A85-2 (+B) or 1Q-11 - Body ground Always 10 kΩ or higher
      A85-1 (+B2) or 1Q-11 - Body ground Always 10 kΩ or higher

    NG
    OK
  5. 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
      C110-81 - Body ground Always Below 1 Ω

    NG
    OK
  6. INSPECT ECM (IGSW VOLTAGE)

    A01WWILE01
    *1 Front view of wire harness connector: (to ECM)

    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
      Tester Connection Switch Condition Specified Condition
      A85-28 (IGSW) - C110-81 (E1) Engine switch on (IG) 11 to 14 V

    OK
    NG
  7. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM)


    1. Disconnect the ECM connector.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A85-28 (IGSW) - 1N-7 Always Below 1 Ω
      A85-28 (IGSW) or 1N-7 - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      OK (w/ Entry and Start System) A
      OK (w/o Entry and Start System) B
      NG C

    B
    A
  8. CHECK HARNESS AND CONNECTOR (SMART KEY ECU ASSEMBLY - INTEGRATION RELAY)


    1. Disconnect the smart key ECU assembly connector.

    2. Disconnect the integration relay connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E149-3 (IG1D) - 1P-2 Always Below 1 Ω
      E149-3 (IG1D) or 1P-2 - Body ground Always 10 kΩ or higher

    OK
    NG