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 current to flow to the EFI relay coil, closing the contacts of the EFI relay and supplying power to terminal +B of the ECM.

WIRING DIAGRAM

A01XJC0E05
*a Ignition Switch
*b P/I-B
*c Battery
*d No. 1 Integration Relay

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CHECK ECM (+B VOLTAGE)

    A01XM9WE02
    Text in Illustration
    *a

    Component with harness connected

    (ECM)

    1. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G183-1 (+B) - C161-5 (E1) Ignition switch ON 11 to 14 V

    OK

    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 (Check for Open)
      Tester Connection Condition Specified Condition
      C161-5 (E1) - Body ground Always Below 1 Ω

    3. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK ECM (IGSW VOLTAGE)

    A01XMOFE02
    Text in Illustration
    *a

    Component with harness connected

    (ECM)

    1. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G183-11 (IGSW) - C161-5 (E1) Ignition switch ON 11 to 14 V

    NG

    INSPECT IGNITION SWITCH ASSEMBLY Click here

    OK

  4. CHECK ECM (MREL VOLTAGE)

    A01XJACE02
    Text in Illustration
    *a

    Component with harness connected

    (ECM)

    1. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G186-10 (MREL) - C161-5 (E1) Ignition switch ON 11 to 14 V

    NG

    REPLACE ECM Click here

    OK

  5. CHECK NO. 1 INTEGRATION RELAY (EFI)

    A01XJ5GE02
    *a No. 1 Integration Relay

    1. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1B-4 - Body ground Ignition switch ON 10 to 14 V
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to No. 1 Integration Relay)

    3. Reconnect the No. 1 integration relay (EFI) connector.


    NG

    REPLACE NO. 1 INTEGRATION RELAY (EFI)

    OK

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


    1. Disconnect the No. 1 integration relay (EFI) connector from the engine room junction 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
      1B-2 - G183-10 (MREL) Always Below 1 Ω
      1B-4 - G183-1 (+B) Always Below 1 Ω
      1B-3 - Body ground Always Below 1 Ω
      1B-2 or G183-10 (MREL) - Body ground Always 10 kΩ or higher
      1B-4 or G183-1 (+B) - Body ground Always 10 kΩ or higher

    4. Reconnect the No. 1 integration relay connector.

    5. Reconnect the ECM connector.


    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (TERMINAL +B OF ECM - BATTERY)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  7. INSPECT IGNITION SWITCH ASSEMBLY


    1. Inspect the ignition switch assembly Click here.


    OK

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

    NG

    REPLACE IGNITION SWITCH ASSEMBLY Click here