SEAT BELT WARNING SYSTEM(w/ Occupant Classification System) TERMINALS OF ECU


  1. CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) AND INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (w/ Rear Seat Belt Warning)

    B0070ETN33

    1. Disconnect the instrument panel junction block assembly and main body ECU (multiplex network body ECU) connectors.

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    2. Reconnect the instrument panel junction block assembly connectors.

    3. 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) Engine switch on (IG) 11 to 14 V
      Engine switch off Below 1 V
      MB-30 (ACC) - Body ground - Ignition power supply (ACC signal) Engine switch on (ACC) 11 to 14 V
      Engine switch off Below 1 V
      MB-11 (GND1) - Body ground - Ground Always Below 1 Ω
      MB-2 (RCTY) - Body ground - Rear door courtesy light switch RH input Rear door RH closed (OFF) 10 kΩ or higher
      Rear door RH open (ON) Below 1 Ω
      MB-13 (LCTY) - Body ground - Rear door courtesy light switch LH input Rear door LH closed (OFF) 10 kΩ or higher
      Rear door LH open (ON) Below 1 Ω

  2. CHECK COMBINATION METER ASSEMBLY

    B004L4PN11

    1. Disconnect the K21 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
      K21-40 (B) - Body ground LA-B - Body ground Battery power supply Always 11 to 14 V
      K21-39 (IG+) - Body ground LA-GR Body ground Ignition power supply Engine switch off Below 1 V
      Engine switch on (IG) 11 to 14 V
      K21-21 (ES) - Body ground W-B - Body ground Ground Always Below 1 Ω
      K21-24 (RLSB) - Body ground SB - 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
      K21-26 (RRSB) - Body ground LG - 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
      K21-25 (RCSB) - Body ground B - 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

    3. Reconnect the K21 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
      K21-18 (RLMT) - Body ground BE - Body ground Rear LH seat belt warning light output signal Engine switch on (IG), rear seat belt warning light (LH) off 11 to 14 V
      Engine switch on (IG), rear seat belt warning light (LH) on Below 1 V
      K21-19 (RCMT) - Body ground R - Body ground Rear center seat belt warning light output signal Engine switch on (IG), rear seat belt warning light (center) off 11 to 14 V
      Engine switch on (IG), rear seat belt warning light (center) on Below 1 V
      K21-20 (RRMT) - Body ground G - Body ground Rear RH seat belt warning light output signal Engine switch on (IG), rear seat belt warning light (RH) off 11 to 14 V
      Engine switch on (IG), rear seat belt warning light (RH) on Below 1 V

  3. AIRBAG SENSOR ASSEMBLY

    B004MU5N04
    Terminal No. Terminal Symbol Destination
    R32-28 LBE+ Front seat inner belt assembly LH
    R32-27 LBE- Front seat inner belt assembly LH

  4. CHECK OCCUPANT DETECTION ECU

    B004IBXN38

    1. Measure the voltage and check for pulses according to the value(s) in the table below.

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      a20-10 (GND) - Body ground W-B - Body ground Ground Always Below 1 V
      a20-6 (IG2) - a20-10 (GND) B - W-B Power source Engine switch on (IG) 11 to 14 V
      a20-9 (BGND) - a20-10 (GND) P - W-B Front passenger buckle switch ground Always Below 1 V
      a20-7 (BSW) - a20-9 (BGND) G - P Front passenger buckle switch signal Always Pulse generation
      a19-1 (SVC1) - a19-5 (SGD1) R - G Front occupant classification sensor LH power supply Engine switch on (IG) 11 to 14 V
      a19-2 (SVC3) - a19-6 (SGD3) GR - W Rear occupant classification sensor LH power supply Engine switch on (IG) 11 to 14 V
      a19-3 (SIG1) - a19-5 (SGD1) P - G Front occupant classification sensor LH signal Engine switch on (IG) Pulse generation
      a19-4 (SIG3) - a19-6 (SGD3) SB - W Rear occupant classification sensor LH signal Engine switch on (IG) Pulse generation
      a19-5 (SGD1) - a20-10 (GND) G - W-B Front occupant classification sensor LH ground Always Below 1 V
      a19-6 (SGD3) - a20-10 (GND) W - W-B Rear occupant classification sensor LH ground Always Below 1 V