ECD SYSTEM ECU Power Source Circuit

DESCRIPTION

When the ignition switch is turned ON, battery positive voltage is applied to the coil, closing the contacts of the EFI relay (Marking: EFI) and supplying power to the terminal +B of the ECM.

WIRING DIAGRAM

A01KG63E01

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK ECM (CHECK VOLTAGE)


    1. A01KGF1E09

      Turn the ignition switch ON.

    2. Check the voltage between terminals of the ECM connector as shown in the table and illustration.

      Voltage

      Terminal

      (Positive terminal ←→ Negative terminal)

      		 Voltage
      +B (E10-1) ←→ E1 (E7-22) 9 - 14 V

    OK

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOM TABLE Click here

    NG

  2. CHECK WIRE HARNESS (ECM - BODY GROUND)


    1. A01KFXGE01

      Disconnect the ECM (E7) connector.

    2. Check the continuity between terminals of the ECM connector as shown in the illustration and table.

      Continuity (Check for open)

      Terminal

      (ECM ←→ ECM(Ground))

      		 Standard
      E1 (E7-22) ←→ Body ground

      Continuity

      (1 Ω or less)

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

  3. CHECK MAIN RELAY


    1. A01KIFKE01
      Text in Illustration
      *1 Ohmmeter
      *a Continuity
      *b No Continuity

      Remove the main relay from the relay block No. 2.

    2. Inspect the relay continuity.


      1. Using an ohmmeter, check that there is continuity between terminals 1 and 2.

      2. Check that there is no continuity between terminals 3 and 5.

    3. A01KGYZE01
      Text in Illustration
      *1 Ohmmeter
      *2 Battery
      *a Continuity

      Inspect the relay operation.


      1. Apply battery voltage across terminals 1 and 2.

      2. Using an ohmmeter, check that there is continuity between terminals 3 and 5.


    NG

    REPLACE MAIN RELAY

    OK

  4. CHECK FUSE (EFI FUSE)


    1. Remove the EFI fuse from the R/B No. 2.

    2. Check the continuity of the EFI fuse.

      Result
      Continuity

    3. Check for short in all harness and components connected to the EFI fuse.


    NG

    REPLACE FUSE

    OK

  5. CHECK WIRE HARNESS (ECM - EFI MAIN RELAY) (a) (EFI MAIN RELAY - BATTERY) (b)


    1. A01KFAFE01

      Check for open and short in harness and connector between the ECM and EFI main relay.


      1. Remove the EFI main relay.

      2. Disconnect the ECM (E10) connector.

      3. Check the continuity between terminals of the EFI main relay (3) of the R/B No. 2 and ECM connector as shown in the illustration and table.

        Continuity (Check for open)

        Terminal

        (EFI main relay of R/B No. 2 ←→ ECM)

        		 Standard
        3 ←→ +B (E10-1) Continuity
        Continuity (Check for short)

        Terminal

        (ECM ←→ ECM(Ground))

        		 Standard
        +B (E10-1) ←→ E1 (E7-22) No continuity
    2. A01KH5LE01

      Check for open in harness and connector between the EFI main relay and battery.


      1. Remove the EFI main relay.

      2. Disconnect the battery positive terminal.

      3. Check continuity between the terminals EFI main relay (5) of R/B No. 2 and battery positive terminal wire.

        Continuity (Check for open)

        Terminal

        (EFI main relay of R/B No. 2 ←→ Battery)

        		 Standard
        5 ←→ Battery positive terminal Continuity

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

  6. CHECK ECM (CHECK VOLTAGE)


    1. A01KGF1E11

      Turn the ignition switch ON.

    2. Check the voltage between terminals of the ECM connectors as shown in the table and illustration.

      Voltage

      Terminal

      (Positive terminal ←→ Negative terminal)

      		 Voltage
      IGSW (E10-9) ←→ E1 (E8-22) 9 - 14 V

    OK

    CHECK ECM (CHECK VOLTAGE) Click here

    NG

  7. CHECK IGNITION OR STARTER SWITCH ASSEMBLY


    1. A01KF8KE01
      Text in Illustration
      *a LOCK
      *b ACC
      *c ON
      *d START

      Remove the lower finish panel.

    2. Disconnect the ignition switch connector.

    3. Check the continuity between the terminals shown below.

      Continuity
      Switch position Terminal No. to continuity
      LOCK - -
      ACC 4 ←→ 9 -
      ON 4 ←→ 9 ←→ 10 5 ←→ 8
      START 3 ←→ 9 ←→ 10 5 ←→ 8

    NG

    REPLACE IGNITION OR STARTER SWITCH ASSEMBLY

    OK

  8. CHECK WIRE HARNESS (ECM - IGNITION SWITCH)


    1. A01KEJZE01

      Disconnect the ignition switch connector.

    2. Disconnect the ECM (E10) connector.

    3. Check the continuity between terminals of the ignition switch and ECM connectors as shown in the illustration and table.

      Continuity (Check for open)

      Terminal

      (Ignition switch ←→ ECM)

      		 Standard
      IG2 (8) ←→ IGSW (E10-9) Continuity
      Continuity (Check for short)

      Terminal

      (ECM ←→ ECM(Ground))

      		 Standard
      IGSW (E10-9) ←→ E1 (E7-22) No continuity

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

  9. CHECK ECM (CHECK VOLTAGE)


    1. A01KGF1E10

      Turn the ignition switch ON.

    2. Check the voltage between terminals of the ECM connectors as shown in the table and illustration.

      Voltage

      Terminal

      (Positive terminal ←→ Negative terminal)

      		 Voltage
      MREL (E10-7) ←→ E1 (E7-22) 9 - 14 V

    OK

    CHECK AND REPLACE ECM Click here

    NG

  10. CHECK HARNESS AND CONNECTOR (ECM - EFI MAIN RELAY) (a) (EFI MAIN RELAY - BODY GROUND) (b)


    1. A01KFAFE02

      Check for open and short in harness and connector between the ECM and EFI main relay.


      1. Remove the EFI main relay.

      2. Disconnect the ECM (E10) connector.

      3. Check the continuity between terminals of the EFI main relay (2) of the R/B No. 2 and ECM connector as shown in the illustration and table.

        Continuity (Check for open)

        Terminal

        (EFI main relay of R/B No. 2 ←→ ECM)

        		 Standard
        2 ←→ MREL (E10-7) Continuity
        Continuity (Check for short)

        Terminal

        (ECM ←→ ECM(Ground))

        		 Standard
        MREL (E10-7) ←→ E1 (E7-22) No continuity
    2. A01KH5LE02

      Check for open and short in harness and connector between the EFI main relay and body ground.


      1. Check the continuity between terminals of the EFI main relay (1) of the R/B No. 2 and body ground as shown in the illustration and table.

        Continuity (Check for open)

        Terminal

        (EFI main relay of R/B No. 2 ←→ Body ground)

        		 Standard
        1 ←→ Body ground Continuity

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

    REPAIR OR REPLACE ENGINE ROOM RELAY BLOCK