SEAT BELT WARNING 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.

      A00Y6QDC01
      *A Main body ECU (multiplex network body ECU) with 1 connector - -
      *1 Main body ECU (multiplex network body ECU) - -
      *a 1 connector - -
      A00Y8J8C01
      *A Main body ECU (multiplex network body ECU) with 2 connectors - -
      *1 Main body ECU (multiplex network body ECU) - -
      *a 2 connectors - -

    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-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
      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
      E22-24 (LCTY) - Body ground* SB - Body ground Rear door courtesy light switch LH input Rear door LH closed (OFF) 10 kΩ or higher
      E22-24 (LCTY) - Body ground* SB - Body ground Rear door courtesy light switch LH input Rear door LH open (ON) Below 1 Ω
      E22-6 (RCTY) - Body ground* LG - Body ground Rear door courtesy light switch RH input Rear door RH closed (OFF) 10 kΩ or higher
      E22-6 (RCTY) - Body ground* LG - Body ground Rear door courtesy light switch RH input Rear door RH open (ON) Below 1 Ω

      • *: w/ Rear Seat Belt Warning

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

  2. CHECK COMBINATION METER ASSEMBLY


    1. Disconnect the E46 combination meter assembly connector.

      A00Y9Z6N02

    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
      E46-39 (IG+) - Body ground P - Body ground Ignition power supply (IG signal) Ignition switch ON → off 11 to 14 V → Below 1 V
      E46-21 (ET) - Body ground BR - Body ground Ground Always Below 1 Ω
      E46-7 (P/SB) - Body ground L - Body ground Front passenger seat belt buckle switch signal Front passenger seat occupied, seat belt fastened 10 kΩ or higher
      E46-7 (P/SB) - Body ground L - Body ground Front passenger seat belt buckle switch signal Front passenger seat occupied, seat belt unfastened Below 1 Ω
      E46-24 (RLSB) - Body ground* Y - Body ground Rear LH seat belt buckle switch signal Rear LH seat belt fastened 10 kΩ or higher
      E46-24 (RLSB) - Body ground* Y - Body ground Rear LH seat belt buckle switch signal Rear LH seat belt unfastened Below 1 Ω
      E46-25 (RCSB) - Body ground* L - Body ground Rear center seat belt buckle switch signal Rear center seat belt fastened 10 kΩ or higher
      E46-25 (RCSB) - Body ground* L - Body ground Rear center seat belt buckle switch signal Rear center seat belt unfastened Below 1 Ω
      E46-26 (RRSB) - Body ground* R - Body ground Rear RH seat belt buckle switch signal Rear RH seat belt fastened 10 kΩ or higher
      E46-26 (RRSB) - Body ground* R - Body ground Rear RH seat belt buckle switch signal Rear RH seat belt unfastened Below 1 Ω

      • *: w/ Rear Seat Belt Warning

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