BACK DOOR CLOSER SYSTEM, Diagnostic DTC:B2251

DTC Code DTC Name
B2251 Back Door Closer Switch Malfunction

DESCRIPTION

The multiplex network door ECU receives signals from the latch switch, initial switch, pawl switch and back door courtesy switch, which are built into the back door lock assembly. Based on these switch signals, the latch position of the back door lock assembly is determined.

DTC No. Detection Item DTC Detection Condition Trouble Area
B2251 Back Door Closer Switch Malfunction While the back door closer is operating, a malfunction is detected in position information from the back door courtesy switch within a specified amount of time.

  • Back door lock assembly

  • Harness or connector

  • Multiplex network door ECU

  • Instrument panel junction block assembly

  • Main body ECU (multiplex network body ECU)

WIRING DIAGRAM

Click here

CAUTION / NOTICE / HINT

Note


  • Inspect the fuses for circuits related to this system before performing the following procedure.

  • If the replacement, removal and installation of the multiplex network door ECU or disconnection of the connectors of the multiplex network door ECU has been performed, initialize the power back door system.

    Click here

  • If the main body ECU (multiplex network body ECU) is replaced, refer to Service Bulletin.

  • As the door control battery is installed between the vehicle battery and main body ECU (multiplex network body ECU), first perform the inspections in On-Vehicle Inspection to confirm that there are no malfunctions in the power source circuit for the main body ECU (multiplex network body ECU) before performing this troubleshooting procedure.*


    • *: w/ Door Control Battery

PROCEDURE


  1. READ VALUE USING GTS


    1. Read the Data List according to the display on the GTS.

      Click here


      Body Electrical > Back Door > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Courtesy SW Back door courtesy switch signal ON or OFF

      ON: Back door open

      OFF: Back door closed

      		 *: Refer to "CONSTRUCTION AND OPERATION"

      Body Electrical > Back Door > Data List
      Tester Display
      Courtesy SW

      *: Refer to "CONSTRUCTION AND OPERATION"

      Click here

      OK
      The display is as specified in the normal condition column.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MULTIPLEX NETWORK DOOR ECU Click here

    NG

  2. INSPECT BACK DOOR LOCK ASSEMBLY


    1. Remove the back door lock assembly.

      Click here

    2. Inspect the back door lock assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE BACK DOOR LOCK ASSEMBLY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (BACK DOOR LOCK ASSEMBLY - MULTIPLEX NETWORK DOOR ECU AND BODY GROUND)


    1. Disconnect the 4A instrument panel junction block assembly connector.

    2. Disconnect the Y12 back door lock assembly connector.

    3. Disconnect the Y25 multiplex network door ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Y12-8 (CTY) - Y25-11 (FUL) Always Below 1 Ω
      Y12-7 (E) - Body ground Always Below 1 Ω
      Y12-8 (CTY) or Y25-11 (FUL) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - MULTIPLEX NETWORK DOOR ECU)


    1. Disconnect the 4A instrument panel junction block assembly connector.

    2. Disconnect the Y25 multiplex network door ECU connector.

    3. Disconnect the Y12 back door lock assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      4A-21 - Y25-11 (FUL) Always Below 1 Ω
      4A-21 or Y25-11 (FUL) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. B0057PSE02

      Remove the instrument panel junction block assembly.

      for LHD:

      Click here

      for RHD:

      Click here

    2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

      for LHD:

      Click here

      for RHD:

      Click here

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A-4 (BCTY) - 4A-21 Always Below 1 Ω
      A-4 (BCTY) or 4A-21 - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    B

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    C

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    A

  6. READ VALUE USING GTS


    1. Disconnect the Y25 multiplex network door ECU connector.

    2. Read the Data List according to the display on the GTS.

      Click here


      Body Electrical > Main Body > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Back Door Courtesy SW Back door courtesy switch signal ON or OFF

      ON: Back door open

      OFF: Back door closed

      		 -

      Body Electrical > Main Body > Data List
      Tester Display
      Back Door Courtesy SW
      OK
      The display is as specified in the normal condition column.
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    A

    REPLACE MULTIPLEX NETWORK DOOR ECU Click here

    B

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    C

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here