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.

      B332798C01

      *A

      Main body ECU (multiplex network body ECU) with 1 connector

      -

      -

      *1

      Main body ECU (multiplex network body ECU)

      -

      -

      *a

      1 connector

      -

      -
      B332794C01

      *A

      Main body ECU (multiplex network body ECU) with 2 connectors

      -

      -

      *1

      Main body ECU (multiplex network body ECU)

      -

      -

      *a

      2 connectors

      -

      -
      B332799C19

      *A

      Main Body ECU (Multiplex Network Body ECU) with 3 Connectors

      -

      -

      *1

      Main Body ECU (Multiplex Network Body ECU)

      -

      -

      *a

      3 Connectors

      -

      -

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

      Tip:

      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.

      B129553N02

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

      Tip:

      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.