SEAT BELT WARNING SYSTEM TERMINALS OF ECU


  1. CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) AND INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

    A005OYIC37
    *A Main Body ECU (Multiplex Network Body ECU) with 1 Connector - -
    A002YIVC32
    *A Main Body ECU (Multiplex Network Body ECU) with 2 Connectors - -

    1. Disconnect the main body ECU (multiplex network body ECU) connectors.

      for LHD: Click here

      for RHD: Click here

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

      Tech Tips

      Measure the values on the wire harness side with the connector disconnected.

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      MB-31 (BECU) - Body ground - Battery power supply Always 11 to 14 V
      MB-32 (IG) - Body ground - Ignition power supply (IG signal) Ignition switch ON → off 11 to 14 V → Below 1 V
      MB-30 (ACC) - Body ground - Ignition power supply (ACC signal) Ignition switch ACC → off 11 to 14 V → Below 1 V
      MB-11 (GND1) - Body ground - Ground Always Below 1 Ω
      MB-18 (DBKL) - Body ground - Driver seat belt buckle switch signal Driver seat belt fastened 10 kΩ or higher
      Driver seat belt unfastened Below 1 Ω
      MB-2 (RCTY) - Body ground - Rear door courtesy light switch RH input Rear door LH closed (OFF) 10 kΩ or higher
      Rear door LH open (ON) Below 1 Ω
      MB-13 (LCTY) - Body ground - Rear door courtesy light switch LH input Rear door RH closed (OFF) 10 kΩ or higher
      Rear door RH open (ON) Below 1 Ω

  2. CHECK COMBINATION METER ASSEMBLY

    A002YQVN27

    1. Disconnect the F4 combination meter assembly connector.

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

      Tech Tips

      Measure the values on the wire harness side with the connector disconnected.

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      F4-40 (B) - Body ground SB - Body ground Battery power supply Always 11 to 14 V
      F4-39 (IG+) - Body ground P - Body ground IG power supply Ignition switch ON → off 11 to 14 V → Below 1 V
      F40-21 (ET) - Body ground W- B - Body ground Ground Always Below 1 Ω
      F4-7 (PKBI) - Body ground GR - Body ground Front passenger seat belt buckle switch signal Front passenger side seat belt fastened and front passenger seat occupied 10 kΩ or higher
      Front passenger side seat belt unfastened and front passenger seat occupied Below 1 Ω
      F4-24 (MSD)* - Body ground V - Body ground Rear LH seat belt buckle switch signal Rear LH seat belt fastened 10 kΩ or higher
      Rear LH seat belt unfastened Below 1 Ω
      F4-25 (MSTI)* - Body ground BE - Body ground Rear center seat belt buckle switch signal Rear center seat belt fastened 10 kΩ or higher
      Rear center seat belt unfastened Below 1 Ω
      F4-26 (MSFM)* - Body ground R - Body ground Rear RH seat belt buckle switch signal Rear RH seat belt fastened 10 kΩ or higher
      Rear RH seat belt unfastened Below 1 Ω

      • *: w/ Rear Seat Belt Warning

    3. Reconnect the F4 combination meter assembly connector.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      F4-3 (RRMT)* - Body ground W - Body ground Rear RH seat belt warning light signal Ignition switch ON, Rear RH seat belt unfastened within 34 seconds after closing rear door Below 1 V
      Ignition switch ON, Rear RH seat belt fastened within 34 seconds after closing rear door 11 to 14 V
      F4-2 (RCMT)* - Body ground V - Body ground Rear center seat belt warning light signal Ignition switch ON, Rear center seat belt unfastened within 34 seconds after closing rear door Below 1 V
      Ignition switch ON, Rear center seat belt fastened within 34 seconds after closing rear door 11 to 14 V
      F4-1 (RLMT)* - Body ground L - Body ground Rear LH seat belt warning light signal Ignition switch ON, Rear LH seat belt unfastened within 34 seconds after closing rear door Below 1 V
      Ignition switch ON, Rear LH seat belt fastened within 34 seconds after closing rear door 11 to 14 V

      • *: w/ Rear Seat Belt Warning