SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

When the ignition switch is turned on (IG), the battery voltage is applied to terminal IGSW of the ECM. The ECM MREL output signal causes a current to flow to the coil, closing the contacts of the EFI relay and supplying power to terminal +B and +B2 of the ECM.

If the ignition switch is turned off, the ECM holds the EFI relay ON for a maximum of 2 seconds to allow for the initial setting of the throttle valve.

WIRING DIAGRAM

A017F9TE04
A017E08E03

INSPECTION PROCEDURE

PROCEDURE


  1. INSPECT ECM (+B AND +B2 VOLTAGE)


    1. A017BQGE17

      Turn the ignition switch on (IG).

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      D31-1 (+B) - B3-1 (E1) Ignition switch on (IG) 9 to 14 V
      D31-2 (+B2) - B3-1 (E1) Ignition switch on (IG) 9 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) Click here

    OK

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

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


    1. A017E35E01

      Disconnect the ECM connector.

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

      Standard resistance
      Check for open
      Tester Connection Condition Specified Condition
      B3-1 (E1) - Body ground Always Below 1 Ω

    3. Reconnect the ECM connector.


    NG

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

    OK

  3. INSPECT ECM (MREL VOLTAGE)


    1. A017BQGE18

      Turn the ignition switch on (IG).

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      D31-8 (MREL) - B3-1 (E1) Ignition switch on (IG) 9 to 14 V

    NG

    INSPECT ECM (IGSW VOLTAGE) Click here

    OK

  4. CHECK FUSE (EFI MAIN AND EFI NO. 2 FUSE)


    1. A017ENJE10

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

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

      Standard resistance
      Tester Connection Condition Specified Condition
      EFI MAIN fuse Always Below 1 Ω
      EFI No. 2 fuse Always Below 1 Ω

    3. Reinstall the fuses.


    NG

    REPLACE FUSE (EFI MAIN OR EFI NO. 2 FUSE)

    OK

  5. INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY (EFI RELAY)


    1. Inspect the EFI relay Click here.


    NG

    REPLACE RELAY (EFI RELAY) Click here

    OK

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


    1. A017CR2E01

      Remove the engine room junction block from the engine room relay block.

    2. Disconnect the ECM connector.

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

      Standard resistance
      Check for open
      Tester Connection Condition Specified Condition
      2E-9 (EFI relay terminal) - D31-8 (MREL) Always Below 1 Ω
      2E-10 (EFI relay terminal) - Body ground Always Below 1 Ω
      Check for short
      Tester Connection Condition Specified Condition
      2E-9 (EFI relay terminal) or D31-8 (MREL) - Body ground Always 10 kΩ or higher

    4. Reinstall the engine room junction block.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A017CR2E02

      Remove the engine room junction block from the engine room relay block.

    2. Disconnect the ECM connector.

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

      Standard resistance
      Check for open
      Tester Connection Condition Specified Condition
      2E-6 (EFI relay terminal) - D31-1 (+B) Always Below 1 Ω
      2E-6 (EFI relay terminal) - D31-2 (+B2) Always Below 1 Ω
      Check for short
      Tester Connection Condition Specified Condition
      2E-6 (EFI relay terminal) or D31-1 (+B) - Body ground Always 10 kΩ or higher
      2E-6 (EFI relay terminal) or D31-2 (+B2) - Body ground Always 10 kΩ or higher

    4. Reinstall the engine room junction block.

    5. Reconnect the ECM connector.


    NG

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

    OK

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

  8. INSPECT ECM (IGSW VOLTAGE)


    1. A017BQGE19

      Turn the ignition switch on (IG).

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      D31-9 (IGSW) - B3-1 (E1) Ignition switch on (IG) 9 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (ECM - IG2 RELAY) Click here

    OK

    REPLACE ECM Click here

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


    1. A017B0EE01

      Remove the IG2 relay from the engine room relay block.

    2. Disconnect the ECM connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      IG2 relay terminal 3 - D31-9 (IGSW) Always Below 1 Ω

    4. Reconnect the ECM connector.

    5. Reinstall the IG2 relay.


    NG

    CHECK FUSE (IGN FUSE) Click here

    OK

  10. INSPECT IG2 RELAY


    1. A017B6E

      Remove the IG2 relay from the engine room relay block.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      3 - 5 When no battery voltage applied to terminals 1 and 2 10 kΩ or higher
      When battery voltage applied to terminals 1 and 2 Below 1 Ω

    3. Reinstall the IG2 relay.


    NG

    REPLACE IG2 RELAY

    OK

  11. CHECK HARNESS AND CONNECTOR (IG2 RELAY POWER SOURCE)


    1. A017ECOE01

      Remove the IG2 relay from the engine room relay block.

    2. Turn the ignition switch on (IG)

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      5 - Body ground Ignition switch on (IG) 9 to 14 V

    4. Reinstall the IG2 relay.


    NG

    CHECK FUSE (IG2 FUSE) Click here

    OK

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


    1. A017ECOE01

      Remove the IG2 relay from the 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 - Body ground Always Below 1 Ω

    3. Reinstall the IG2 relay.

      Result
      Result Proceed to
      NG A
      OK (w/o Smart entry and star system) B
      OK (w/ Smart entry and star system) C

    B

    CHECK HARNESS AND CONNECTOR (IGNITION SWITCH - IG2 RELAY) Click here

    C

    CHECK HARNESS AND CONNECTOR (IG2 RELAY - MAIN BODY ECU, IG2 RELAY - BODY GROUND) Click here

    A

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IG2 RELAY - BODY GROUND)

  13. CHECK FUSE (IG2 FUSE)


    1. A017ENJE08

      Remove the IG2 fuse from the engine room relay block.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      IG2 fuse Always Below 1 Ω

    3. Reinstall the IG2 fuse


    NG

    REPLACE FUSE (IG2 FUSE)

    OK

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

  14. CHECK FUSE (IGN FUSE)


    1. A017CXCE01

      Remove the IGN fuse from the instrument panel junction block.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      IGN fuse Always Below 1 Ω

    3. Reinstall the IGN fuse.


    NG

    REPLACE FUSE (IGN FUSE)

    OK

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

  15. CHECK HARNESS AND CONNECTOR (IGNITION SWITCH - IG2 RELAY)


    1. A017E41E01

      Remove the IG2 relay from the engine room relay block.

    2. Disconnect the ignition switch connector.

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

      Standard resistance
      Check for open
      Tester Connection Condition Specified Condition
      D21-6 (IG2) - IG2 relay terminal 1 Always Below 1 Ω
      Check for short
      Tester Connection Condition Specified Condition
      D21-6 (IG2) or IG2 relay terminal 1 - Body ground Always 10 kΩ or higher

    4. Reinstall the IG2 relay.

    5. Reconnect the ignition switch connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION SWITCH - IG2 RELAY)

    OK

  16. INSPECT IGNITION SWITCH


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


    NG

    REPLACE IGNITION SWITCH Click here

    OK

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

  17. CHECK HARNESS AND CONNECTOR (IG2 RELAY - MAIN BODY ECU, IG2 RELAY - BODY GROUND)


    1. A017FCAE01

      Remove the IG2 relay from the engine room relay block.

    2. Remove the instrument panel junction block (main body ECU).

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

      Standard resistance (Check for open)
      Tester Connection Condition Specified Condition
      IG2 relay terminal (1) - D6-11 (IG2D) Always Below 1 Ω
      IG2 relay terminal (2) - Body ground Always Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Condition Specified Condition
      D6-11 (IG2D) - Body ground Always 10 kΩ or higher

    4. Reinstall the IG2 relay.

    5. Reconnect the main body ECU connector.


    NG

    CHECK SMART ENTRY AND START SYSTEM Click here

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR