ECD SYSTEM ECM Power Source Circuit

DESCRIPTION

When the engine switch is turned on (IG), the battery voltage is applied to terminal IGSW of the ECM. The MREL output signal from ECM causes a current to flow to the coil, closing the contacts of the EFI MAIN1 relay and supplying power to terminal +B, +B2 and +B3 of the ECM.

WIRING DIAGRAM

B001FM6E01

CAUTION / NOTICE / HINT

Note


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

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

PROCEDURE


  1. CHECK TERMINAL VOLTAGE (+B, +B2 AND +B3 TERMINAL VOLTAGE)


    1. B001IKQE01
      Text in Illustration
      *a

      Component with harness connected

      (ECM)

      Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      G185-2 (+B) - C152-1 (E1) Engine switch on (IG) 11 to 14 V
      G185-3 (+B2) - C152-1 (E1) Engine switch on (IG) 11 to 14 V
      G185-4 (+B3) - C152-1 (E1) Engine switch on (IG) 11 to 14 V

    OK

    CHECK PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    NG

  2. 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
      C152-1 (E1) - Body ground Always Below 1 Ω

    3. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK TERMINAL VOLTAGE (IGSW TERMINAL VOLTAGE)


    1. B001IKQE02
      Text in Illustration
      *a

      Component with harness connected

      (ECM)

      Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      G185-18 (IGSW) - C152-1 (E1) Engine switch on (IG) 11 to 14 V

    NG

    INSPECT NO. 1 INTEGRATION RELAY (IG2) Click here

    OK

  4. CHECK TERMINAL VOLTAGE (MREL TERMINAL VOLTAGE)


    1. B001IKQE03
      Text in Illustration
      *a

      Component with harness connected

      (ECM)

      Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      G184-14 (MREL) - C152-1 (E1) Engine switch on (IG) 11 to 14 V

    NG

    REPLACE ECM Click here

    OK

  5. INSPECT NO. 1 INTEGRATION RELAY (EFI MAIN1)


    1. Inspect the No. 1 integration relay (EFI MAIN1) Click here.


    NG

    REPLACE NO. 1 INTEGRATION RELAY (EFI MAIN1)

    OK

  6. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - ECM)


    1. Remove the No. 1 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
      1K-7 - G184-14 (MREL) Always Below 1 Ω
      1J-10 - G185-2 (+B) Always Below 1 Ω
      1J-10 - G185-3 (+B2) Always Below 1 Ω
      1J-10 - G185-4 (+B3) Always Below 1 Ω
      1J-3 - Body ground Always Below 1 Ω
      1K-7 - G184-14 (MREL) - Body ground and other terminals Always Below 1 Ω
      1J-10 or G185-2 (+B) - Body ground and other terminals Always 10 kΩ or higher
      1J-10 or G185-3 (+B2) - Body ground and other terminals Always 10 kΩ or higher
      1J-10 or G185-4 (+B3) - Body ground and other terminals Always 10 kΩ or higher

    4. Reinstall the No. 1 integration relay.

    5. Reconnect the ECM connector.


    OK

    CHECK TERMINAL VOLTAGE (NO. 1 INTEGRATION RELAY) Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  7. INSPECT NO. 1 INTEGRATION RELAY (IG2)


    1. Inspect the No. 1 integration relay (IG2 relay) Click here.


    NG

    REPLACE NO. 1 INTEGRATION RELAY (IG2)

    OK

  8. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - ECM)


    1. Remove the No. 1 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
      1J-7 - G185-18 (IGSW) Always Below 1 Ω
      1J-3 - Body ground Always Below 1 Ω
      1J-7 or G185-18 (IGSW) - Body ground and other terminals Always 10 kΩ or higher

    4. Reinstall the No. 1 integration relay.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. CHECK TERMINAL VOLTAGE (NO. 1 INTEGRATION RELAY)


    1. B001D8GE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to No. 1 Integration Relay)

      Remove the No. 1 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 Engine switch on (IG) 11 to 14 V

    3. Reinstall the No. 1 integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - NO. 1 INTEGRATION RELAY)

    OK

  10. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - NO. 1 INTEGRATION RELAY)


    1. Disconnect the power management control ECU connector.

    2. Remove the No. 1 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
      G50-8 (IG2D) - 1J-6 Always Below 1 Ω
      G50-8 (IG2D) or 1J-6 - Body ground and other terminals Always 10 kΩ or higher

    4. Reconnect the power management control ECU connector.

    5. Reinstall the No. 1 integration relay.


    OK

    CHECK ENTRY AND START SYSTEM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR