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 short or open in the front seat inner belt buckle switch circuit (for passenger side).

DTC No. DTC Detection Condition Trouble Area
B2075 Open or short in front seat inner belt (buckle switch) circuit

  • CAN communication system

  • Front seat inner belt assembly RH (for LHD)

  • Front seat inner belt assembly LH (for RHD)

  • Seat belt control ECU

  • Wire harness or connector

WIRING DIAGRAM

A005ERME05
for LHD
*a Front Seat Inner Belt Assembly RH
*b Seat Belt Control ECU Assembly
A005BHHE03
for RHD
*a Front Seat Inner Belt Assembly LH
*b Seat Belt Control ECU Assembly

PROCEDURE


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


    1. Disconnect the S23 front seat inner belt assembly RH connector (for LHD).

    2. Disconnect the R33 front seat inner belt assembly LH connector (for RHD).

    3. Disconnect the L3 seat belt control ECU connector.

    4. Measure the resistance of the wire harness side connectors.

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      S23-4 (RBE-) - L3-3 (RBL-) Always Below 1 Ω
      S23-5 (RBE+) - L3-4 (RBL+) Always Below 1 Ω
      S23-4 (RBE-) - Body ground Always 10 kΩ or higher
      S23-5 (RBE+) - Body ground Always 10 kΩ or higher
      Standard Resistance
      for RHD
      Tester Connection Condition Specified Condition
      R33-4 (LBE-) - L3-6 (LBL-) Always Below 1 Ω
      R33-5 (LBE+) - L3-5 (LBL+) Always Below 1 Ω
      R33-4 (LBE-) - Body ground Always 10 kΩ or higher
      R33-5 (LBE+) - Body ground Always 10 kΩ or higher

    5. Reconnect the L3 seat belt control ECU connector.

    6. Reconnect the R33 front seat inner belt assembly RH connector (for LHD).

    7. Reconnect the S23 front seat inner belt connector (for RHD).


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FRONT SEAT INNER BELT - SEAT BELT CONTROL ECU)

    OK

  2. CHECK SEAT BELT CONTROL ECU


    1. A005CSZE02
      Text in Illustration
      *a Seat Belt Control ECU

      Fasten the passenger side seat belt.

    2. Turn the power switch on (IG).

    3. Using an oscilloscope, check the waveform of the seat belt control ECU between the connector terminals.

      Tech Tips

      Voltage is only output for 20 ms of a 100 ms cycle.

      Item Contents
      Terminal

      L3-3 (RBL-) - L3-4 (RBL+) (for LHD)

      L3-5 (LBL+) - L3-6 (LBL-) (for RHD)
      Tool setting 2V/DIV, 20ms/DIV
      Vehicle Condition Power switch on (IG)
      OK
      Approximately 5 V

    4. Proceed to the next step based on the inspection result.

      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    A

    REPLACE SEAT BELT CONTROL ECU Click here

    B

    REPLACE FRONT SEAT INNER BELT ASSEMBLY RH (for LHD) Click here

    C

    REPLACE FRONT SEAT INNER BELT ASSEMBLY LH (for RHD) Click here