PRE-CRASH SAFETY SYSTEM TERMINALS OF ECU


  1. CHECK SEAT BELT CONTROL ECU

    A004QU1E01

    1. for LHD:

      Disconnect the A52 and A53 ECU connectors.

    2. for RHD:

      Disconnect the D109 and D110 ECU connectors.

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

      for LHD
      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      A52-7 (+B) - Body ground B - Body ground Battery Always 11 to 14 V
      A52-8 (PGND) - Body ground W-B - Body ground Body ground Always Below 1 Ω
      A53-8 (IG1) - Body ground SB - Body ground Seat belt control ECU power supply Ignition switch ON 11 to 14 V
      Ignition switch off Below 1 V
      for RHD
      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      D109-7 (+B) - Body ground B - Body ground Battery Always 11 to 14 V
      D109-8 (PGND) - Body ground W-B - Body ground Body ground Always Below 1 Ω
      D110-8 (IG1) - Body ground G - Body ground Seat belt control ECU power supply Ignition switch ON 11 to 14 V
      Ignition switch off Below 1 V

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

    4. for LHD:

      Reconnect the A52 and A53 ECU connectors.

    5. for RHD:

      Reconnect the D109 and D110 ECU connectors.

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

      for LHD
      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      A52-2 (MOR+) - A52-1 (MOR-) V - GR Seat belt motor RH power supply Ignition switch ON 4.0 to 8.5 V
      Ignition switch off Below 1 V
      A52-3 (MOL+) - A52-4 (MOL-) L - BR Seat belt motor LH power supply Ignition switch ON 4.0 to 8.5 V
      Ignition switch off Below 1 V
      A53-5 (LBL+) - A53-6 (LBL-) B - LG Front seat inner belt LH signal Ignition switch ON, front seat belt LH fastened

      Pulse generation

      (see waveform)
      A53-3 (RBL-) - A53-4 (RBL+) L - P Front seat inner belt RH signal Ignition switch ON, front seat belt RH fastened

      Pulse generation

      (see waveform)
      for RHD
      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      D109-2 (MOR+) - D109-1 (MOR-) V - GR Seat belt motor RH power supply Ignition switch ON 4.0 to 8.5 V
      Ignition switch off Below 1 V
      D109-3 (MOL+) - D109-4 (MOL-) L - BR Seat belt motor LH power supply Ignition switch ON 4.0 to 8.5 V
      Ignition switch off Below 1 V
      D110-5 (LBL+) - D110-6 (LBL-) B - LG Front seat inner belt LH signal Ignition switch ON, front seat belt LH fastened

      Pulse generation

      (see waveform)
      D110-3 (RBL-) - D110-4 (RBL+) L - P Front seat inner belt RH signal Ignition switch ON, front seat belt RH fastened

      Pulse generation

      (see waveform)

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


      1. A004U9CE01

        Using an oscilloscope, check the waveform.

        Measurement Condition
        Item Content
        Tester Connection

        • A53-5 (LBL+) - A53-6 (LBL-)*1

        • A53-3 (RBL-) - A53-4 (RBL+)*1

        • D110-3 (RBL-) - D110-4 (RBL+)*2

        • D110-5 (LBL+) - D110-6 (LBL-)*2
        Tool Setting 2 V/DIV., 20 ms/DIV.
        Vehicle Condition Ignition switch ON, front seat belt fastened

        *1: for LHD

        *2: for RHD

  2. CHECK DRIVING SUPPORT ECU

    A004U94E02

    1. Disconnect the D14 ECU connector.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      D14-30 (B) - Body ground L - Body ground Power supply Ignition switch ON 11 to 14 V
      Ignition switch off Below 1 V
      D14-25 (GND) - Body ground BR - Body ground Body ground Always Below 1 Ω
      D14-5 (PBSW) - Body ground Y - Body ground Pre-crash brake cancel switch signal Pre-crash brake cancel switch on Below 1 Ω
      Pre-crash brake cancel switch off 10 kΩ or higher

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