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ECD SYSTEM ECM Power Source Circuit

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DTC Code DTC Name
  ECM Power Source Circuit
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DESCRIPTION

When the ignition switch is turned to ON, the battery voltage is applied to terminal IGSW of the ECM. The ECM "MREL" output signal causes a current to flow to the coil, closing the contacts of the MAIN relay and supplying power to terminal +B of the ECM.

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WIRING DIAGRAM

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INSPECTION PROCEDURE

Note:

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

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

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PROCEDURE


  1. Click here

    INSPECT ENGINE ROOM NO. 1 RELAY BLOCK


    1. A01IP0GE03

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

    2. Remove the EFI MAIN relay from the engine room No. 1 relay block.

    3. 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
      5 (EFI MAIN relay holder) - Body ground Always 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1A-2 - Body ground Always Below 1 Ω
      1 (EFI MAIN relay holder) - Body ground Always Below 1 Ω

    5. Reinstall the integration relay.

    6. Reinstall the EFI MAIN relay.

      Table 1. Text in Illustration
      *1 Engine Room No. 1 Relay Block
      *2 EFI MAIN Relay
      *a

      Front view of wire harness connector

      (to Integration Relay)

  2. Click here

    INSPECT INTEGRATION RELAY (IG2 RELAY)


    1. Inspect the integration relay (IG2 RELAY) (Click here).


  3. Click here

    INSPECT EFI MAIN RELAY


    1. Inspect the EFI MAIN relay (Click here).


  4. Click here

    CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 1 RELAY BLOCK - ECM)


    1. A01IQU7E03

      Check the wire harness between the ECM and engine room No. 1 relay block.

    2. Disconnect the ECM connector.

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

    4. Remove the EFI MAIN relay from the engine room No. 1 relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A51-45 (MREL) - 2 (EFI MAIN relay holder) Always Below 1 Ω
      A51-1 (+B) - 3 (EFI MAIN relay holder) Always Below 1 Ω
      A51-20 (+B2) - 3 (EFI MAIN relay holder) Always Below 1 Ω
      A51-25 (IGSW) - 1A-4 Always Below 1 Ω
      A51-45 (MREL) or 2 (EFI MAIN relay holder) - Body ground Always 10 kΩ or higher
      A51-1 (+B) or 3 (EFI MAIN relay holder) - Body ground Always 10 kΩ or higher
      A51-20 (+B2) or 3 (EFI MAIN relay holder) - Body ground Always 10 kΩ or higher
      A51-25 (IGSW) or 1A-4 - Body ground Always 10 kΩ or higher
      Table 2. Text in Illustration
      *1 Engine Room No. 1 Relay Block
      *2 EFI MAIN Relay
      *a

      Front view of wire harness connector

      (to ECM)
      *b

      Front view of wire harness connector

      (to Integration Relay)

    6. Reconnect the ECM connector.

    7. Reinstall the integration relay.

    8. Reinstall the EFI MAIN relay.


  5. Click here

    INSPECT ECM (IGSW VOLTAGE)


    1. A01ISHJE18

      Disconnect the ECM connectors.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A51-25 (IGSW) - C69-109 (E1) Ignition switch ON 11 to 14 V
      Table 3. Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)
      Table 4. Result
      Result Proceed to
      OK A
      NG (w/ Entry and Start System) B
      NG (w/o Entry and Start System) C

    4. Reconnect the ECM connectors.


  6. Click here

    CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - ENGINE ROOM NO. 1 RELAY BLOCK)


    1. Remove the power management control ECU.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H70-8 (IG2D) - 1A-3 Always Below 1 Ω
      H70-8 (IG2D) or 1A-3 - Body ground Always 10 kΩ or higher
      Table 5. Text in Illustration
      *1 Engine Room No. 1 Relay Block
      *a

      Front view of wire harness connector

      (to Integration Relay)
      *b

      Rear view of wire harness connector

      (to Power Management Control ECU)

    4. Reinstall the power management control ECU.

    5. Reinstall the integration relay.


  7. Click here

    CHECK HARNESS AND CONNECTOR (IGNITION SWITCH - ENGINE ROOM NO. 1 RELAY BLOCK)


    1. Disconnect the ignition switch connector.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H6-6 (IG2) - 1A-3 Always Below 1 Ω
      H6-6 (IG2) or 1A-3 - Body ground Always 10 kΩ or higher
      Table 6. Text in Illustration
      *1 Engine Room No. 1 Relay Block
      *a

      Front view of wire harness connector

      (to Ignition Switch)
      *b

      Front view of wire harness connector

      (to Integration Relay)

    4. Reconnect the ignition switch connector.

    5. Reinstall the integration relay.


  8. Click here

    INSPECT IGNITION SWITCH ASSEMBLY


    1. A01IPUYE04

      Disconnect the ignition switch connector.

    2. Measure the resistance of the terminals shown below.

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      Between any terminals OFF 1 MΩ or higher
      2 - 3 ACC Below 1 Ω
      2 - 4, 6 - 7 ON Below 1 Ω
      1 - 2, 2 - 4, 6 - 7, 7 - 8 START Below 1 Ω
      Table 7. Text in Illustration
      *a

      Component without harness connected

      (Ignition Switch)

    3. Reconnect the ignition switch connector.


  9. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  10. Click here

    REPLACE INTEGRATION RELAY

  11. Click here

    REPLACE EFI MAIN RELAY

  12. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  13. Click here

    REPLACE ECMClick here

  14. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  15. Click here

    CHECK ENTRY AND START SYSTEMClick here

  16. Click here

    REPLACE IGNITION SWITCH ASSEMBLYClick here

  17. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION SWITCH - BATTERY)