SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

When the engine switch is turned on (IG), the battery voltage is applied to the IGSW terminal of the ECM.

The output signal from the MREL terminal of the ECM causes a current to flow to the coil of the EFI-MAIN relay, closing the contacts and supplying power to terminals +B and +B2 of the ECM.

WIRING DIAGRAM

B006OZVE01

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 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D110-53 (E1) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK TERMINAL VOLTAGE (IGSW TERMINAL VOLTAGE)


    1. B006LQ3C15
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A53-4 (IGSW) - Body ground Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT IG2 RELAY Click here

    OK

  3. INSPECT EFI-MAIN RELAY


    1. Inspect the EFI-MAIN relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE EFI-MAIN RELAY

    OK

  4. CHECK HARNESS AND CONNECTOR (EFI-MAIN RELAY - ECM)


    1. Disconnect the ECM connector.

    2. Remove the EFI-MAIN relay from the No. 1 engine room relay block.

      Tech Tips

      Remove the EFI-MAIN NO. 2 and A/F relays connected between the checked terminals as the coil inside the relay influences the measurement value.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (EFI-MAIN relay) - A53-46 (MREL) Always Below 1 Ω
      5 (EFI-MAIN relay) - A53-2 (+B) Always Below 1 Ω
      5 (EFI-MAIN relay) - A53-3 (+B2) Always Below 1 Ω
      1 (EFI-MAIN relay) or A53-46 (MREL) - Body ground and other terminals Always 10 kΩ or higher
      5 (EFI-MAIN relay) or A53-2 (+B) - Body ground and other terminals Always 10 kΩ or higher
      5 (EFI-MAIN relay) or A53-3 (+B2) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK TERMINAL VOLTAGE (POWER SOURCE OF EFI-MAIN RELAY)

    B006P8WC01
    *1 No. 1 Engine Room Relay Block
    *2 EFI-MAIN Relay

    1. Remove the EFI-MAIN relay from the No. 1 engine room relay block.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      3 (EFI-MAIN relay) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - EFI-MAIN RELAY)

    OK

  6. CHECK HARNESS AND CONNECTOR (EFI-MAIN RELAY - BODY GROUND)


    1. Remove the EFI-MAIN relay from the No. 1 engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 (EFI-MAIN relay) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  7. INSPECT IG2 RELAY


    1. Inspect the IG2 relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE IG2 RELAY

    OK

  8. CHECK HARNESS AND CONNECTOR (IG2 RELAY - ECM)


    1. Disconnect the ECM connector.

    2. Remove the IG2 relay from the No. 1 engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 (IG2 relay) - A53-4 (IGSW) Always Below 1 Ω
      3 (IG2 relay) or A53-4 (IGSW) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. CHECK TERMINAL VOLTAGE (POWER SOURCE OF IG2 RELAY)

    B006P1KC01
    *1 No. 1 Engine Room Relay Block
    *2 IG2 Relay

    1. Remove the IG2 relay from the No. 1 engine room relay block.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      5 (IG2 relay) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - IG2 RELAY)

    OK

  10. CHECK HARNESS AND CONNECTOR (IG2 RELAY - BODY GROUND)


    1. Remove the IG2 relay from the No. 1 engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 (IG2 relay) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - IG2 RELAY)


    1. Disconnect the certification ECU (smart key ECU assembly) connector.

    2. Remove the IG2 relay from the No. 1 engine room relay block.

      Tech Tips

      Remove the junction block assembly LH (IG1 NO. 1, IG1 NO. 2 and IG1 NO. 3 relays) and IG1 NO. 4 relay connected between the checked terminals as the coil inside the relay influences the measurement value.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A58-3 (IG1D) - 1 (IG2 relay) Always Below 1 Ω
      A58-3 (IG1D) or 1 (IG2 relay) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    CHECK SMART ENTRY AND START SYSTEM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR