СИСТЕМА ECD ECM Power Source Circuit

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.

WIRING DIAGRAM

A01IRKCE02

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.

PROCEDURE


  1. INSPECT ENGINE ROOM NO. 1 RELAY BLOCK


    1. A01IP0GE03
      Text in Illustration
      *1 Engine Room No. 1 Relay Block
      *2 EFI MAIN Relay
      *a

      Front view of wire harness connector

      (to Integration Relay)

      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.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT INTEGRATION RELAY (IG2 RELAY)


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


    NG

    REPLACE INTEGRATION RELAY

    OK

  3. INSPECT EFI MAIN RELAY


    1. Inspect the EFI MAIN relay Click here.


    NG

    REPLACE EFI MAIN RELAY

    OK

  4. CHECK WIRE HARNESS (ENGINE ROOM NO. 1 RELAY BLOCK - ECM)


    1. A01IQU7E03
      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)

      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

    6. Reconnect the ECM connector.

    7. Reinstall the integration relay.

    8. Reinstall the EFI MAIN relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT ECM (IGSW VOLTAGE)


    1. A01ISHJE17
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)
      *b

      Front view of wire harness connector

      (to ECM)

      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
      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.


    B

    CHECK WIRE HARNESS (POWER MANAGEMENT CONTROL ECU - ENGINE ROOM NO. 1 RELAY BLOCK) Click here

    C

    CHECK WIRE HARNESS (IGNITION SWITCH - ENGINE ROOM NO. 1 RELAY BLOCK) Click here

    A

    REPLACE ECM Click here

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

    A01IPL5E08
    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)

    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

    4. Reinstall the power management control ECU.

    5. Reinstall the integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    CHECK ENTRY AND START SYSTEM Click here

  7. CHECK WIRE HARNESS (IGNITION SWITCH - ENGINE ROOM NO. 1 RELAY BLOCK)

    A01IOBGE05
    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)

    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

    4. Reconnect the ignition switch connector.

    5. Reinstall the integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. INSPECT IGNITION SWITCH ASSEMBLY


    1. A01IPUYE04
      Text in Illustration
      *a

      Component without harness connected

      (Ignition Switch)

      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

    3. Reconnect the ignition switch connector.


    NG

    REPLACE IGNITION SWITCH ASSEMBLY Click here

    OK

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