LIN COMMUNICATION SYSTEM, Diagnostic DTC:B2785

DTC Code DTC Name
B2785 Communication Malfunction between ECUs Connected by LIN

DESCRIPTION

The certification ECU intermittently monitors the LIN communication bus between the components related to certification. DTC B2785 is stored when a malfunction in the LIN communication bus between the components related to certification is detected continuously 3 times.

DTC Code DTC Detection Condition Trouble Area
B2785 The certification ECU detects a malfunction in the LIN communication bus between components related to certification continuously 3 times.

  • Certification ECU

  • Power management control ECU

  • ID code box

  • Steering lock actuator assembly (steering lock ECU)

  • Harness or connector

WIRING DIAGRAM

A01IPOCE13

INSPECTION PROCEDURE

Note

When using the intelligent tester with the ignition switch off to troubleshoot:

Connect the intelligent tester to the vehicle, and turn a courtesy light switch on and off at 1.5 second intervals until communication between the intelligent tester and vehicle begins.

Tech Tips

When DTC B2785 and B2287 are output simultaneously, perform troubleshooting for DTC B2785 first.

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - ID CODE BOX)


    1. A01IRNGE03
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Certification ECU)
      *2

      Front view of wire harness connector

      (to ID Code Box)

      Disconnect the H51 ECU connector.

    2. Disconnect the H111 box connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H51-29 (LIN) - H111-3 (LIN1) Always Below 1 Ω
      H51-29 (LIN) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK FOR DTC


    1. Connect the H51 ECU connector.

    2. Connect the H111 box connector.

    3. Disconnect the H71 ECU connector.

    4. Clear the DTCs Click here.

    5. Check for DTCs.

      Result
      Result Proceed to
      DTC B2785 is output A
      DTC B2785 is not output B

    B

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    A

  3. CHECK FOR DTC


    1. Connect the H71 ECU connector.

    2. Disconnect the H54 ECU connector.

    3. Clear the DTCs Click here.

    4. Check for DTCs.

      Result
      Result Proceed to
      DTC B2785 is output A
      DTC B2785 is not output B

    B

    REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU) Click here

    A

  4. CHECK FOR DTC


    1. Connect the H54 ECU connector.

    2. Disconnect the H111 box connector.

    3. Clear the DTCs Click here.

    4. Check for DTCs.

      Result
      Result Proceed to
      DTC B2785 is output A
      DTC B2785 is not output B

    B

    REPLACE ID CODE BOX Click here

    A

    REPLACE CERTIFICATION ECU

  5. REPLACE POWER MANAGEMENT CONTROL ECU


    1. for LHD:


      1. Temporarily replace the power management control ECU with a new or normally functioning one Click here.

    2. for RHD:


      1. Temporarily replace the power management control ECU with a new or normally functioning one Click here.

    3. Clear the DTCs Click here.


    NEXT

  6. CHECK FOR DTC


    1. Check for DTCs.

      Result
      Result Proceed to
      DTC B2785 is not output A
      DTC B2785 is output B

    B

    REPLACE CERTIFICATION ECU

    A

    END (POWER MANAGEMENT CONTROL ECU IS DEFECTIVE)

  7. REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU)


    1. Temporarily replace the steering lock actuator (steering lock ECU) with a new one Click here.

    2. Clear the DTCs Click here.


    NEXT

  8. CHECK FOR DTC


    1. Check for DTCs.

      Result
      Result Proceed to
      DTC B2785 is not output A
      DTC B2785 is output B

    B

    REPLACE CERTIFICATION ECU

    A

    END (STEERING LOCK ECU IS DEFECTIVE)

  9. REPLACE ID CODE BOX


    1. Temporarily replace the ID code box with a new one.

    2. Clear the DTCs Click here.


    NEXT

  10. CHECK FOR DTC


    1. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC B2785 is not output A
      DTC B2785 is output B

    B

    REPLACE CERTIFICATION ECU

    A

    END (ID CODE BOX IS DEFECTIVE)