SFI SYSTEM Ignition Circuit

DESCRIPTION

A direct ignition system is used on this vehicle. The direct ignition system is a 1 cylinder ignition system which ignites one cylinder with one ignition coil assembly. In the 1 cylinder ignition system, one spark plug is connected to the end of the secondary winding. High voltage is generated in the secondary winding and is applied directly to the spark plug. The spark of the spark plug passes from the center electrode to the ground electrode.

The ECM determines the ignition timing and transmits the ignition signals for each cylinder. Using the ignition signal, the ECM turns on and off the power transistor inside the igniter, which switches on and off a current to the primary coil. When the current to the primary coil is cut off, high voltage is generated in the secondary coil and this voltage is applied to the spark plugs to create sparks inside the cylinders.

WIRING DIAGRAM

A0047XAE01

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CHECK TERMINAL VOLTAGE (POWER SOURCE OF NO. 1 IGNITION COIL)


    1. A004AUAC12
      *a

      Front view of wire harness connector

      (to No. 1 ignition coil)

      Disconnect the No. 1 ignition coil connectors.

    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
      B14-1 (+B) - B14-4 (GND) Ignition switch ON 11 to 14 V
      B16-1 (+B) - B16-4 (GND) Ignition switch ON 11 to 14 V
      B18-1 (+B) - B18-4 (GND) Ignition switch ON 11 to 14 V
      B20-1 (+B) - B20-4 (GND) Ignition switch ON 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (NO. 1 IGNITION COIL - BODY GROUND) Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (NO. 1 IGNITION COIL - ECM)


    1. Disconnect the B14, B16, B18 and B20 No. 1 ignition coil connectors.

    2. Disconnect the B112 ECM connector.*1

    3. Disconnect the B118 ECM connector.*2

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

      *1: for LHD

      *2: for RHD

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      B112-75 (IGT1) - B14-3 (IGT1) Always Below 1 Ω
      B112-74 (IGT2) - B16-3 (IGT2) Always Below 1 Ω
      B112-73 (IGT3) - B18-3 (IGT3) Always Below 1 Ω
      B112-72 (IGT4) - B20-3 (IGT4) Always Below 1 Ω
      B112-75 (IGT1) or B14-3 (IGT1) - Body ground and other terminals Always 10 kΩ or higher
      B112-74 (IGT2) or B16-3 (IGT2) - Body ground and other terminals Always 10 kΩ or higher
      B112-73 (IGT3) or B18-3 (IGT3) - Body ground and other terminals Always 10 kΩ or higher
      B112-72 (IGT4) or B20-3 (IGT4) - Body ground and other terminals Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      B118-75 (IGT1) - B14-3 (IGT1) Always Below 1 Ω
      B118-74 (IGT2) - B16-3 (IGT2) Always Below 1 Ω
      B118-73 (IGT3) - B18-3 (IGT3) Always Below 1 Ω
      B118-72 (IGT4) - B20-3 (IGT4) Always Below 1 Ω
      B118-75 (IGT1) or B14-3 (IGT1) - Body ground and other terminals Always 10 kΩ or higher
      B118-74 (IGT2) or B16-3 (IGT2) - Body ground and other terminals Always 10 kΩ or higher
      B118-73 (IGT3) or B18-3 (IGT3) - Body ground and other terminals Always 10 kΩ or higher
      B118-72 (IGT4) or B20-3 (IGT4) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  3. CHECK HARNESS AND CONNECTOR (NO. 1 IGNITION COIL - BODY GROUND)


    1. Disconnect the B14, B16, B18 and B20 No. 1 ignition coil connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B14-4 (GND) - Body ground Always Below 1 Ω
      B16-4 (GND) - Body ground Always Below 1 Ω
      B18-4 (GND) - Body ground Always Below 1 Ω
      B20-4 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (NO. 1 IGNITION COIL - NO. 1 INTEGRATION RELAY)


    1. Disconnect the B14, B16, B18 and B20 No. 1 ignition coil connectors.

    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
      B14-1 (+B) - 1E-2 Always Below 1 Ω
      B16-1 (+B) - 1E-2 Always Below 1 Ω
      B18-1 (+B) - 1E-2 Always Below 1 Ω
      B20-1 (+B) - 1E-2 Always Below 1 Ω
      B14-1 (+B) or 1E-2 - Body ground and other terminals Always 10 kΩ or higher
      B16-1 (+B) or 1E-2 - Body ground and other terminals Always 10 kΩ or higher
      B18-1 (+B) or 1E-2 - Body ground and other terminals Always 10 kΩ or higher
      B20-1 (+B) or 1E-2 - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Inspect the No. 1 integration relay.

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    CHECK ECM POWER SOURCE CIRCUIT Click here

    NG

    REPLACE NO. 1 INTEGRATION RELAY Click here