SFI SYSTEM (w/o EGR System) ECM Power Source Circuit

DESCRIPTION

When the power switch is turned on (IG), auxiliary battery voltage is applied to IGSW of the ECM. The output signal from the MREL terminal of the ECM causes a current to flow to the coil, closing the contacts of the No. 2 integration relay (EFI MAIN relay) and supplying power to either terminal +B and +B2 of the ECM.

WIRING DIAGRAM

A01JBHXE09

INSPECTION PROCEDURE

Note


  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work Click here.

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

PROCEDURE


  1. 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
      D28-104 (E1) - Body ground Always Below 1 Ω

    3. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - BODY GROUND)

    OK

  2. CHECK TERMINAL VOLTAGE (IGSW VOLTAGE)


    1. A01J9BKE36
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

    2. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A57-28 (IGSW) - Body ground Power switch on (IG) 11 to 14 V

    4. Reconnect the ECM connector.


    NG

    INSPECT NO. 2 INTEGRATION RELAY (IG2 RELAY) Click here

    OK

  3. INSPECT NO. 2 INTEGRATION RELAY (EFI MAIN RELAY)


    1. Inspect the No. 2 integration relay (EFI MAIN relay) Click here.


    NG

    REPLACE NO. 2 INTEGRATION RELAY (EFI MAIN RELAY) Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (EFI MAIN RELAY) - ECM)


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

    2. Disconnect the No. 2 integration relay connector.

    3. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      1B-4 - A57-1 (+B2) Always Below 1 Ω
      1B-4 - A57-2 (+B) Always Below 1 Ω
      1B-2 - A57-6 (MREL) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      1B-4 or A57-1 (+B2) - Body ground Always 10 kΩ or higher
      1B-4 or A57-2 (+B) - Body ground Always 10 kΩ or higher
      1B-2 or A57-6 (MREL) - Body ground Always 10 kΩ or higher

    5. Reconnect the ECM connector.

    6. Reconnect the No. 2 integration relay connector.

    7. Reinstall the No. 2 integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 2 INTEGRATION RELAY (EFI MAIN RELAY) - ECM)

    OK

  5. CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (EFI MAIN RELAY) - AUXILIARY BATTERY)


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

    2. Disconnect the No. 2 integration relay connector.

    3. Disconnect the negative (-) auxiliary battery terminal.

    4. Disconnect the positive (+) auxiliary battery terminal.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      1C-1 - Positive (+) auxiliary battery terminal Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      1C-1 or Positive (+) auxiliary battery terminal - Body ground Always 10 kΩ or higher

    6. Reconnect the No. 2 integration relay connector.

    7. Reinstall the No. 2 integration relay.

    8. Reconnect the positive (+) auxiliary battery terminal.

    9. Reconnect the negative (-) auxiliary battery terminal.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 2 INTEGRATION RELAY (EFI MAIN RELAY) - AUXILIARY BATTERY)

    OK

  6. CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (EFI MAIN RELAY) - BODY GROUND)


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

    2. Disconnect the No. 2 integration relay connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1B-3 - Body ground Always Below 1 Ω

    4. Reconnect the No. 2 integration relay connector.

    5. Reinstall the No. 2 integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 2 INTEGRATION RELAY (EFI MAIN RELAY) - BODY GROUND)

    OK

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

  7. INSPECT NO. 2 INTEGRATION RELAY (IG2 RELAY)


    1. Inspect the No. 2 integration relay (IG2 relay) Click here.


    NG

    REPLACE NO. 2 INTEGRATION RELAY (IG2 RELAY) Click here

    OK

  8. CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (IG2 RELAY) - ECM)


    1. Disconnect the ECM connector.

    2. Remove the No. 2 integration relay from the engine room relay block and junction block assembly.

    3. Disconnect the No. 2 integration relay connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      1A-4 - A57-28 (IGSW) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      1A-4 or A57-28 (IGSW) - Body ground Always 10 kΩ or higher

    5. Reconnect the ECM connector.

    6. Reconnect the No. 2 integration relay connector.

    7. Reinstall the No. 2 integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 2 INTEGRATION RELAY (IG2 RELAY) - ECM)

    OK

  9. CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (IG2 RELAY) - AUXILIARY BATTERY)


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

    2. Disconnect the No. 2 integration relay connector.

    3. Disconnect the negative (-) auxiliary battery terminal.

    4. Disconnect the positive (+) auxiliary battery terminal.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      1C-1 - Positive (+) auxiliary battery terminal Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      1C-1 or Positive (+) auxiliary battery terminal - Body ground Always 10 kΩ or higher

    6. Reconnect the No. 2 integration relay connector.

    7. Reinstall the No. 2 integration relay.

    8. Reconnect the positive (+) auxiliary battery terminal.

    9. Reconnect the negative (-) auxiliary battery terminal.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 2 INTEGRATION RELAY (IG2 RELAY) - AUXILIARY BATTERY)

    OK

  10. CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (IG2 RELAY) - BODY GROUND)


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

    2. Disconnect the No. 2 integration relay connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1A-3 - Body ground Always Below 1 Ω

    4. Reconnect the No. 2 integration relay connector.

    5. Reinstall the No. 2 integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 2 INTEGRATION RELAY (IG2 RELAY) - BODY GROUND)

    OK

  11. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - NO. 2 INTEGRATION RELAY (IG2 RELAY))


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

    2. Disconnect the No. 2 integration relay connector.

    3. Disconnect the power management control ECU connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      A22-2 (IG2D) - 1A-2 Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A22-2 (IG2D) or 1A-2 - Body ground Always 10 kΩ or higher

    5. Reconnect the No. 2 integration relay connector.

    6. Reinstall the No. 2 integration relay.

    7. Reconnect the power management control ECU connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - NO. 2 INTEGRATION RELAY (IG2 RELAY))

    OK

    CHECK ENTRY AND START SYSTEM Click here