SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned to ON (IG), auxiliary battery voltage is applied to the IGSW terminal of the ECM. The output signal from the MREL terminal of the ECM causes current to flow to the coil of the No. 1 integration relay (EFI MAIN relay), closing the contact and supplying power to terminals +B and +B2 of the ECM.

WIRING DIAGRAM

A01UYUEE01

CAUTION / NOTICE / HINT

Note

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 C10 ECM connector (for LHD).

    2. Disconnect the C9 ECM connector (for RHD).

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      C10-16 (E1) - Body ground Always Below 1 Ω
      for RHD
      Tester Connection Condition Specified Condition
      C9-16 (E1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK TERMINAL VOLTAGE (IGSW VOLTAGE)


    1. A01V1ASE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

    2. Turn the ignition switch to ON (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A28-37 (IGSW) - Body ground Ignition switch ON (IG) 11 to 14 V

    NG

    INSPECT NO. 1 INTEGRATION RELAY (IG2 RELAY) Click here

    OK

  3. INSPECT NO. 1 INTEGRATION RELAY (EFI MAIN RELAY)


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


    NG

    REPLACE NO. 1 INTEGRATION RELAY (EFI MAIN RELAY) Click here

    OK

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


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

    2. Disconnect the A28 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2C-4 - A28-2 (+B) Always Below 1 Ω
      2C-4 - A28-3 (+B2) Always Below 1 Ω
      2C-2 - A28-46 (MREL) Always Below 1 Ω
      2C-4 or A28-2 (+B) - Body ground Always 10 kΩ or higher
      2C-4 or A28-3 (+B2) - Body ground Always 10 kΩ or higher
      2C-2 or A28-46 (MREL) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - BODY GROUND)


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

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      2C-3 - Body ground Always Below 1 Ω

    OK

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  6. INSPECT NO. 1 INTEGRATION RELAY (IG2 RELAY)


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


    NG

    REPLACE NO. 1 INTEGRATION RELAY (IG2 RELAY) Click here

    OK

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


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

    2. Disconnect the A28 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2D-4 - A28-37 (IGSW) Always Below 1 Ω
      2D-4 or A28-37 (IGSW) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK TERMINAL VOLTAGE (POWER SOURCE OF NO. 1 INTEGRATION RELAY)


    1. A01V1NCE03
      Text in Illustration
      *a

      Front view of wire harness connector

      (to No. 1 Integration Relay)

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

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      2E-1 - Body ground Always 11 to 14 V

    NG

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

    OK

  9. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - BODY GROUND)


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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2D-2 - Body ground Always Below 1 Ω
      Result
      Result Proceed to
      OK (w/ Power switch) A
      OK (w/o Power switch) B
      NG C

    B

    CHECK HARNESS AND CONNECTOR (IGNITION OR STARTER SWITCH ASSEMBLY - NO. 1 INTEGRATION RELAY) Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

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


    1. Disconnect the A27 power management control ECU connector.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A27-2 (IG2D) - 2D-3 Always Below 1 Ω
      A27-2 (IG2D) or 2D-3 - Body ground Always 10 kΩ or higher

    OK

    GO TO SMART KEY SYSTEM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  11. CHECK HARNESS AND CONNECTOR (IGNITION OR STARTER SWITCH ASSEMBLY - NO. 1 INTEGRATION RELAY)


    1. Disconnect the F11 ignition or starter switch assembly connector.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F11-6 (IG2) - 2D-3 Always Below 1 Ω
      F11-6 (IG2) or 2D-3 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. INSPECT IGNITION OR STARTER SWITCH ASSEMBLY


    1. Inspect the ignition or starter switch assembly Click here.


    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION OR STARTER SWITCH ASSEMBLY - AUXILIARY BATTERY)

    NG

    REPLACE IGNITION OR STARTER SWITCH ASSEMBLY Click here