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)

  • ID code box (immobiliser code ECU)

  • Steering lock actuator assembly

  • Harness or connector

WIRING DIAGRAM

A004FD8E02
*a ID Code Box (Immobiliser Code ECU)
*b Certification ECU (Smart Key ECU Assembly)
*c Steering Lock Actuator Assembly
*d LIN Communication Line

CAUTION / NOTICE / HINT

Note


  • If the certification ECU (smart key ECU assembly), ID code box (immobiliser code ECU), steering lock ECU (steering lock actuator assembly) is replaced, refer to Service Bulletin.

  • When using the GTS to troubleshoot with the ignition switch off: Connect the GTS to the DLC3, and turn the courtesy switch on and off at 1.5-second intervals until communication between the GTS 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 F86 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the F43 ID code box (immobiliser code ECU) connector.

    3. Disconnect the F44 steering lock actuator assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F86-17 (LIN) - F43-2 (LIN1) Always Below 1 Ω
      F86-17 (LIN) - F44-5 (LIN) Always Below 1 Ω
      F86-17 (LIN) or F43-2 (LIN1) - Body ground Always 10 kΩ or higher
      F86-17 (LIN) or F44-5 (LIN) - 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 F86 certification ECU (smart key ECU assembly) connector.

    2. Reconnect the F44 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 F43 ID code box (immobiliser code ECU) connector.

    2. Disconnect the F44 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