LIN COMMUNICATION SYSTEM, Diagnostic DTC:B2785

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

DESCRIPTION

The certification ECU (smart key ECU assembly) 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 No. DTC Detection Condition Trouble Area
B2785 The certification ECU (smart key ECU assembly) detects a malfunction in the LIN communication bus between components related to certification continuously 3 times.

  • Certification ECU (smart key ECU assembly)

  • Steering lock actuator assembly

  • ID code box (immobiliser code ECU)

  • Harness or connector

WIRING DIAGRAM

B004732E17
*a Steering Lock Actuator Assembly
*b Certification ECU (Smart Key ECU Assembly)
*c ID Code Box (Immobiliser Code ECU)
*d LIN Communication Line

CAUTION / NOTICE / HINT

Note


  • Before replacing the certification ECU (smart key ECU assembly), refer to the entry and start system (for Entry Function) Click here.

  • If the steering lock actuator assembly is replaced, register the ECU code.

  • If the ID code box (immobiliser code ECU) is replaced, register the ECU code and ECU communication ID.

  • 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.

PROCEDURE


  1. CLEAR DTC


    1. Clear the DTCs Click here.


    NEXT

  2. CHECK FOR DTC


    1. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC 2785 is output A
      DTC 2785 is not output B

    B

    USE SIMULATION METHOD TO CHECK Click here

    A

  3. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - EACH ECU)


    1. Disconnect the F63 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the F61 steering lock actuator assembly connector.

    3. Disconnect the F60 ID code box (immobiliser code ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F63-17 (LIN) - F61-5 (LIN) Always Below 1 Ω
      F63-17 (LIN) - F60-2 (LIN1) Always Below 1 Ω
      F63-17 (LIN) or F61-5 (LIN) - Body ground Always 10 kΩ or higher
      F63-17 (LIN) or F60-2 (LIN1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK DTC OUTPUT (ID CODE BOX (IMMOBILISER CODE ECU))


    1. Reconnect the F63 certification ECU (smart key ECU assembly) connector.

    2. Reconnect the F61 steering lock actuator assembly connector.

    3. Clear the DTCs Click here.

    4. After 10 seconds have elapsed, check if the trouble occurs again.

    5. Check for DTCs Click here.

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

    B

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU)

    A

  5. CHECK DTC OUTPUT (STEERING LOCK ACTUATOR ASSEMBLY)


    1. Reconnect the F60 ID code box (immobiliser code ECU) connector.

    2. Disconnect the F61 steering lock actuator assembly connector.

    3. Clear the DTCs Click here.

    4. After 10 seconds have elapsed, check if the trouble occurs again.

    5. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC B2785 is output A
      DTC B2785 is not output (for RHD) B
      DTC B2785 is not output (for LHD) C

    A

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    B

    REPLACE STEERING LOCK ACTUATOR ASSEMBLY Click here

    C

    REPLACE STEERING LOCK ACTUATOR ASSEMBLY Click here