SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

When the engine switch is turned to on (IG), 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 contacts of the EFI MAIN relay and supplying power to terminals +B and +B2 of the ECM.

WIRING DIAGRAM

B004726E01

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)


    1. Disconnect the A116 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A116-35 (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 VOLTAGE)


    1. Disconnect the ECM connectors.

      B00459KC01
      *1 ECM *a

      Front view of wire harness connector

      (to ECM)

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A116-26 (IGSW) - A116-35 (E1) Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

  3. CHECK TERMINAL VOLTAGE (+B, +B2, +B3 VOLTAGE)


    1. Disconnect the ECM connectors.

      B00459KC02
      *1 ECM *a

      Front view of wire harness connector

      (to ECM)

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A116-36 (+B) - A116-35 (E1) Engine switch on (IG) 11 to 14 V
      A116-24 (+B2) - A116-35 (E1) Engine switch on (IG) 11 to 14 V
      A116-12 (+B3) - A116-35 (E1) Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (ECM - EFI MAIN RELAY) Click here

    OK

  4. CHECK TERMINAL VOLTAGE (MREL VOLTAGE)


    1. Disconnect the ECM connectors.

      B00459KC09
      *1 ECM *a

      Front view of wire harness connector

      (to ECM)

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A116-41 (MREL) - A116-35 (E1) Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

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


    1. Disconnect the A116 ECM connector.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A116-41 (MREL) - 1 (EFI MAIN relay holder) Always Below 1 Ω
      A116-41 (MREL) or 1 (EFI MAIN relay holder) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT EFI MAIN RELAY


    1. Inspect the EFI MAIN relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE EFI MAIN RELAY

    OK

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


    1. B0046CVC01
      *a No. 2 Engine Room Relay Block Assembly
      *b EFI MAIN Relay Holder

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

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      2 (EFI MAIN relay holder) - Body ground Always 11 to 14 V
      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

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


    1. Disconnect the A116 ECM connector.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A116-36 (+B) - 3 (EFI MAIN relay holder) Always Below 1 Ω
      A116-24 (+B2) - 3 (EFI MAIN relay holder) Always Below 1 Ω
      A116-12 (+B3) - 3 (EFI MAIN relay holder) Always Below 1 Ω
      A116-36 (+B) or 3 (EFI MAIN relay holder) - Body ground and other terminals Always 10 kΩ or higher
      A116-24 (+B2) or 3 (EFI MAIN relay holder) - Body ground and other terminals Always 10 kΩ or higher
      A116-12 (+B3) or 3 (EFI MAIN relay holder) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. INSPECT EFI MAIN RELAY


    1. Inspect the EFI MAIN relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE EFI MAIN RELAY

    OK

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


    1. B0046CVC01
      *a No. 2 Engine Room Relay Block Assembly
      *b EFI MAIN Relay Holder

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

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      5 (EFI MAIN relay holder) - Body ground Always 11 to 14 V
      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

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


    1. Inspect the No. 1 integration relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

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

    OK

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


    1. Disconnect the A116 ECM connector.

    2. Disconnect the No. 1 integration relay connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A116-26 (IGSW) - 1D-17 Always Below 1 Ω
      A116-26 (IGSW) or 1D-17 - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

    B0045MHC05
    *a Engine Room Relay Block Assembly *b No. 1 Integration Relay
    *c

    Front view of wire harness connector

    (to No. 1 integration relay)

    		 - -

    1. Disconnect the No. 1 integration relay connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1C-1 - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

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


    1. Disconnect the No. 1 integration relay connector.

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

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

    NG

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

    OK

  15. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - NO. 1 INTEGRATION RELAY)


    1. Disconnect the F65 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the No. 1 integration relay connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F65-9 (IG2D) - 1D-17 Always Below 1 Ω
      F65-9 (IG2D) or 1D-17 - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    CHECK ENTRY AND START SYSTEM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR