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


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


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

      B000LKXE20
      Text in Illustration
      *A for LHD *B for RHD

    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.

      Tester Connection Wiring Color Terminal Description Condition Specified Condition
      MB-30 (BECU) - Body ground - Battery power supply Always 11 to 14 V
      MB-31 (ALTB) - 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-29 (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
      I12-3 (GND2) - Body ground W-B - 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
      MB-18 (DBKL) - Body ground - Driver seat belt buckle switch signal Driver seat belt unfastened Below 1 Ω

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

  2. CHECK COMBINATION METER ASSEMBLY


    1. Disconnect the I18 combination meter assembly connector.

      B000KMHE01

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

      Tech Tips

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

      Tester Connection Wiring Color Terminal Description Condition Specified Condition
      I18-20 (ES) - Body ground BR - Body ground Ground Always Below 1 Ω

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

    3. Reconnect the I18 combination meter assembly connector.

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

      Tester Connection Wiring Color Terminal Description Condition Specified Condition
      I18-1 (B) - Body ground W - Body ground Battery power supply Always 11 to 14 V
      I18-13 (IG+) - Body ground L - Body ground

      Ignition power supply

      (IG signal)

      		 Ignition switch off Below 1 V
      I18-13 (IG+) - Body ground L - Body ground

      Ignition power supply

      (IG signal)

      		 Ignition switch ON 11 to 14 V

      If the result is not as specified, the combination meter assembly may have a malfunction.