SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned to ON, the 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 EFI-MAIN NO. 1 relay and supplying power to either terminal +B or +B2 of the ECM.

WIRING DIAGRAM

A005QB7E02

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 C63 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C63-59 (E1) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

  2. CHECK TERMINAL VOLTAGE (IGSW TERMINAL VOLTAGE)


    1. A005P2XC77
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A38-6 (IGSW) - Body ground Ignition switch ON 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT NO. 1 INTEGRATION RELAY Click here

    OK

  3. INSPECT EFI-MAIN NO. 1 relay


    1. Inspect the EFI-MAIN NO. 1 relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE EFI-MAIN NO.1 relay

    OK

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


    1. Disconnect the A38 ECM connector.

    2. Remove the EFI-MAIN NO. 1 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
      A38-46 (MREL) - 1 (EFI-MAIN NO. 1 relay holder) Always Below 1 Ω
      A38-2 (+B) - 3 (EFI-MAIN NO. 1 relay holder) Always Below 1 Ω
      A38-3 (+B2) - 3 (EFI-MAIN NO. 1 relay holder) Always Below 1 Ω
      A38-46 (MREL) or 1 (EFI-MAIN NO. 1 relay holder) - Body ground and other terminals Always 10 kΩ or higher
      A38-2 (+B) or 3 (EFI-MAIN NO. 1 relay holder) - Body ground and other terminals Always 10 kΩ or higher
      A38-3 (+B2) or 3 (EFI-MAIN NO. 1 relay holder) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - EFI-MAIN NO. 1 RELAY)

    OK

  5. CHECK TERMINAL VOLTAGE (POWER SOURCE OF EFI-MAIN NO. 1 RELAY)


    1. A005PM0C01
      *1 No. 1 Engine Room Relay Block
      *2 EFI-MAIN NO. 1 Relay Holder

      Remove the EFI-MAIN NO. 1 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 (EFI-MAIN NO. 1 relay holder) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

  6. CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 1 RELAY - BODY GROUND)


    1. A005PM0C01
      *1 No. 1 Engine Room Relay Block
      *2 EFI-MAIN NO. 1 Relay Holder

      Remove the EFI-MAIN NO. 1 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 NO. 1 relay holder) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI-MAIN NO. 1 RELAY - BODY GROUND)

  7. INSPECT NO. 1 INTEGRATION RELAY


    1. Inspect the No.1 integration relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE NO. 1 INTEGRATION RELAY Click here

    OK

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


    1. Disconnect the A38 ECM connector.

    2. Disconnect the 1A 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
      A38-6 (IGSW) - 1A-9 Always Below 1 Ω
      A38-6 (IGSW) or 1A-9 - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

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


    1. A005OBSC02
      *a Front view of wire harness connector (to No. 1 integration relay)

      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
      1A-10 - 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

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


    1. A005OBSC02
      *a Front view of wire harness connector (to No. 1 integration relay)

      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
      1A-8 - Body ground Always Below 1 Ω
      Result
      Result Proceed to
      OK (w/ Entry and Start System) A
      OK (w/o Entry and Start System) B
      NG C

    B

    INSPECT IGNITION OR STARTER SWITCH ASSEMBLY Click here

    C

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

    A

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


    1. Disconnect the F1 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the 1A 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
      F1-17 (IG1D) - 1A-7 Always Below 1 Ω
      F1-17 (IG1D) or 1A-7 - 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

  12. INSPECT IGNITION OR STARTER SWITCH ASSEMBLY


    1. Inspect the ignition or starter switch assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE IGNITION OR STARTER SWITCH ASSEMBLY

    OK

  13. CHECK HARNESS AND CONNECTOR (IGNITION OR STARTER SWITCH ASSEMBLY - INTEGRATION RELAY)


    1. Disconnect the F12 ignition or starter switch assembly connector.

    2. Disconnect the 1A integration relay connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F12-8 (IG1) - 1A-7 Always Below 1 Ω
      F12-8 (IG1) or 1A-7 - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION OR STARTER SWITCH ASSEMBLY - INTEGRATION RELAY)