PRE-CRASH SAFETY SYSTEM, Diagnostic DTC:B2075

DTC Code DTC Name
B2075 Passenger Side Seat Belt Buckle Switch Circuit Malfunction

DESCRIPTION

This DTC is stored when there is a malfunction in the front seat inner belt buckle switch circuit for the passenger side.

DTC Code DTC Detection Condition Trouble Area
B2075 Malfunction in the front seat inner belt (buckle switch) circuit.

  • Harness or connector

  • Front seat inner belt (for passenger side)

  • Seat belt control ECU

WIRING DIAGRAM

A01ES3AE04

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (FRONT SEAT INNER BELT - SEAT BELT CONTROL ECU)


    1. A01EQLAE04

      Disconnect the c45*1 or c46*2 front seat inner belt connector.


      • *1: for LHD

      • *2: for RHD

    2. Disconnect the E42 seat belt control ECU connector.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      c45-2 (+) - E42-5 (PBK+) Always Below 1 Ω
      c45-1 (E) - E42-6 (PBK-)
      c45-2 (+) or E42-5 (PBK+) - Body ground 1 MΩ higher
      c45-1 (E) or E42-6 (PBK-) - Body ground
      for RHD
      Tester Connection Condition Specified Condition
      c46-2 (+) - E42-5 (PBK+) Always Below 1 Ω
      c46-1 (E) - E42-6 (PBK-)
      c46-2 (+) or E42-5 (PBK+) - Body ground 1 MΩ higher
      c46-1 (E) or E42-6 (PBK-) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK SEAT BELT CONTROL ECU


    1. A01EQSTE03

      Reconnect the E42 seat belt control ECU connector.

    2. Disconnect the c45*1 or c46*2 front seat inner belt connector.


      • *1: for LHD

      • *2: for RHD

    3. Use an oscilloscope to check the waveform of the seat belt control ECU between the connector terminals.

      Measurement Condition
      Item Content
      Tester Connection E42-5 (PBK+) - E42-6 (PBK-)
      Tool Setting 5 V/DIV., 20 ms./DIV.
      Switch Condition

      Engine switch on (IG)

      Front passenger side seat belt fastened (Buckle switch on)
      OK
      Output voltage is between 4.5 and 5.5 V for 20 ms every 100 ms.
      Result
      Result Proceed to

      OK

      (for LHD)

      		 A

      OK

      (for RHD)

      		 B

      NG

      (for LHD)

      		 C

      NG

      (for RHD)

      		 D

    B

    REPLACE SEAT BELT CONTROL ECU Click here

    C

    REPLACE FRONT SEAT INNER BELT RH (for Passenger Side) Click here

    D

    REPLACE FRONT SEAT INNER BELT LH (for Passenger Side) Click here

    A

    REPLACE SEAT BELT CONTROL ECU Click here