SFI SYSTEM(w/ Canister Pump Module) ECM Power Source Circuit

DESCRIPTION

When the engine switch is turned 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 EFI-MAIN NO. 1 relay, closing the contacts and supplying power to terminals +B and +B2 of the ECM.

WIRING DIAGRAM

A01QSXHE01
*a Certification ECU (Smart Key ECU Assembly)
*b EFI-MAIN NO. 1
*c FL MAIN
*d Battery

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (IG2 RELAY VOLTAGE)


    1. A01QTH9C03
      *1 Engine Room Relay Block and Junction Block Assembly
      *2 IG2 Relay

      Remove the IG2 relay from the engine room relay block and junction block assembly.

    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
      IG2 relay terminal 1 - Body ground Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - IG2 RELAY) Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (BATTERY - IG2 RELAY, EFI-MAIN NO. 1 RELAY)


    1. A01QTH9C03
      *1 Engine Room Relay Block and Junction Block Assembly
      *2 IG2 Relay

      Remove the IG2 relay from the engine room relay block and junction block assembly.

    2. A01QRU5C01
      *1 Engine Room Relay Block and Junction Block Assembly
      *2 EFI-MAIN NO. 1 Relay

      Remove the EFI-MAIN NO. 1 relay from the engine room relay block and junction block assembly.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      IG2 relay terminal 3 - Body ground Always 11 to 14 V
      EFI-MAIN NO. 1 relay terminal 5 - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT IG2 RELAY, EFI-MAIN NO. 1 RELAY


    1. Inspect the IG2 relay.

      Click here

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

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE IG2 RELAY OR EFI-MAIN NO. 1 RELAY

    OK

  4. CHECK HARNESS AND CONNECTOR (IG2 RELAY, EFI-MAIN NO. 1 RELAY - BODY GROUND)


    1. Remove the IG2 relay from the engine room relay block and junction block assembly.

    2. Remove the EFI-MAIN NO. 1 relay from the engine room relay block and junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      IG2 relay terminal 2 - Body ground Always Below 1 Ω
      EFI-MAIN NO. 1 relay terminal 2 - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (IG2 RELAY, EFI-MAIN NO. 1 RELAY - ECM)


    1. Remove the IG2 relay from the engine room relay block and junction block assembly.

    2. Remove the EFI-MAIN NO. 1 relay from the engine room relay block and junction block assembly.

    3. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      IG2 relay terminal 5 - A62-37 (IGSW) Always Below 1 Ω
      EFI-MAIN NO. 1 relay terminal 3 - A62-2 (+B) Always Below 1 Ω
      EFI-MAIN NO. 1 relay terminal 3 - A62-3 (+B2) Always Below 1 Ω
      EFI-MAIN NO. 1 relay terminal 1 - A62-46 (MREL) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. 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
      B77-16 (E1) - 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. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - IG2 RELAY)


    1. Remove the IG2 relay from the engine room relay block and junction block assembly.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G82-9 (IG2D) - IG2 relay terminal 1 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    GO TO ENTRY AND START SYSTEM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR