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PRE-CRASH SAFETY SYSTEM TERMINALS OF ECU

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  1. A0008EME02

    CHECK SEAT BELT CONTROL ECU


    1. Disconnect the H77 and H78 seat belt control ECU connectors.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      H77-7 (+B) - Body ground B - Body ground Auxiliary battery voltage Power switch off 11 to 14 V
      H77-8 (PGND) - Body ground W-B - Body ground Body ground Always Below 1 Ω
      H78-8 (IG1) - Body ground V - Body ground Seat belt control ECU power supply Power switch on (IG) 11 to 14 V
      Power switch off Below 1 V
      Tip:

      If the result is not as specified, there may be a malfunction on the wire harness side.

    3. Reconnect the H77 and H78 seat belt control ECU connectors.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      H77-2 (MOR+) - H77-1 (MOR-) G - B Seat belt motor RH power supply Power switch on (IG) 4.0 to 8.5 V
      Power switch off Below 1 V
      H77-3 (MOL+) - H77-4 (MOL-) R - W Seat belt motor LH power supply Power switch on (IG) 4.0 to 8.5 V
      Power switch off Below 1 V
      H78-5 (PBK+) - H78-6 (PBK-) B - W Front seat inner belt assembly RH line Power switch on (IG), front seat belt fastened → unfastened

      Pulse generation

      (See waveform 1)
      H78-6 (PBK-) - Body ground W - Body ground Front seat inner belt assembly RH line Always Below 1 Ω
      Tip:

      If the result is not as specified, the ECU may be malfunctioning.

    5. A0003IHE02

      Using an oscilloscope, check waveform 1.

      Table 1. Text in Illustration
      *a Front seat belt fastened *b Front seat belt unfastened
      Table 2. Measurement Condition (Waveform 1)
      Item Content
      Tester Connection H78-5 (PBK+) - H78-6 (PBK-)
      Tool Setting 2 V/DIV., 20 ms./DIV.
      Condition Power switch on (IG), front seat belt fastened → unfastened
  2. A0006BGE02

    CHECK DRIVING SUPPORT ECU ASSEMBLY


    1. Disconnect the H75 driving support ECU assembly connector.

      Note:

      Do not apply excessive force to the connector. If a force of 10 kg or more is applied, the connector may be broken.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      H75-30 (B) - Body ground V - Body ground Power supply Power switch on (IG) 11 to 14 V
      Power switch off Below 1 V
      H75-5 (PBSW) - Body ground G - Body ground Pre-crash system cancel switch Pre-crash system cancel switch assembly on Below 1 Ω
      Pre-crash system cancel switch assembly off 10 kΩ or higher
      H75-27 (STP-) - Body ground W - Body ground Stop light switch signal input Brake pedal depressed 7.5 to 14 V
      Brake pedal released Below 1 V
      H75-28 (ST1-) - Body ground GR - Body ground Stop light switch signal input Power switch on (IG), brake pedal released 7.5 to 14 V
      Power switch on (IG), brake pedal depressed Below 1 V
      H75-25 (GND) - Body ground W-B - Body ground Body ground Always Below 1 Ω
      Tip:

      If the result is not as specified, there may be a malfunction on the wire harness side.

    3. Reconnect the H75 driving support ECU assembly connector.

    4. Check the pulse according to the value(s) in the table below.

      Terminal No. (Symbols) Wiring Color Terminal Description Condition Specified Condition
      H75-40 (CA1P) - H75-25 (GND) B - W-B CAN communication signal Power switch on (IG)

      Pulse generation

      (See waveform 1)
      H75-18 (CA1N) - H75-25 (GND) W - W-B CAN communication signal Power switch on (IG)

      Pulse generation

      (See waveform 2)
      H75-39 (CA2H) - H75-25 (GND) R - W-B CAN communication signal Power switch on (IG)

      Pulse generation

      (See waveform 3)
      H75-17 (CA2L) - H75-25 (GND) LG - W-B CAN communication signal Power switch on (IG)

      Pulse generation

      (See waveform 4)
    5. A0005RIE05

      Waveform 1


      1. CAN communication signal

        Item Content
        Tester Connection H75-40 (CA1P) - H75-25 (GND)
        Tool Setting 1 V/DIV., 10 μsec./DIV.
        Condition Power switch on (IG)
    6. A0006YCE01

      Waveform 2


      1. CAN communication signal

        Item Content
        Tester Connection H75-18 (CA1N) - H75-25 (GND)
        Tool Setting 1 V/DIV., 10 μsec./DIV.
        Condition Power switch on (IG)
    7. A0005RIE05

      Waveform 3


      1. CAN communication signal

        Item Content
        Tester Connection H75-39 (CA2H) - H75-25 (GND)
        Tool Setting 1 V/DIV., 10 μsec./DIV.
        Condition Power switch on (IG)
        Tip:

        The waveform varies depending on the CAN communication signal.

    8. A0006YCE01

      Waveform 4


      1. CAN communication signal

        Item Content
        Tester Connection H75-17 (CA2L) - H75-25 (GND)
        Tool Setting 1 V/DIV., 10 μsec./DIV.
        Condition Power switch on (IG)
        Tip:

        The waveform varies depending on the CAN communication signal.