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) monitors communication between all the ECUs connected to the certification bus lines. When the certification ECU (smart key ECU assembly) detects errors in communication with all the ECUs connected to the certification bus lines at a set interval and 3 times in a row, DTC B2785 will be stored.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B2785

Communication Malfunction between ECUs Connected by LIN

  • Errors in LIN communication between ECUs or an open or short in communication lines

  • LIN communication error detected by the certification ECU (smart key ECU assembly) 3 times in a row.

  • Certification ECU (smart key ECU assembly)

  • Steering lock ECU (steering lock actuator assembly)

  • ID code box (immobiliser code ECU)

  • Wire harness or connector

  • STRG LOCK fuse

  • ECU-B NO. 2 fuse

WIRING DIAGRAM

B333672E01

CAUTION / NOTICE / HINT

Note:

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

  • If the certification ECU (smart key ECU assembly) is replaced, register the keys (refer to Service Bulletin).

  • If the steering lock ECU (steering lock actuator assembly) is replaced, register the ECU code (refer to Service Bulletin).

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

  • Before performing the inspection, check that DTC B2786, B2789 is not output.

    Click here

PROCEDURE

  1. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - EACH ECU)

    1. Disconnect the E35 certification ECU (smart key ECU assembly) connector.

    2. Disconnect the E37 steering lock ECU (steering lock actuator assembly) connector.

    3. Disconnect the E87 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

      E35-17 (LIN) - E37-5 (LIN)

      Always

      Below 1 Ω

      E35-17 (LIN) - E87-2 (LIN)

      Always

      Below 1 Ω

      E35-17 (LIN) - Body ground

      Always

      10 kΩ or higher

      E37-5 (LIN) - Body ground

      Always

      10 kΩ or higher

      E87-2 (LIN) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK DTC OUTPUT (STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY))

    1. Reconnect the E35 certification ECU (smart key ECU assembly) connector.

    2. Reconnect the E87 ID code box (immobiliser code ECU) connector.

    3. Clear the DTCs.

      Click here

      Body Electrical > Entry&Start > Clear DTCs

    4. Recheck for DTCs.

      Body Electrical > Entry&Start > Trouble Codes

    Result

    Result

    Proceed to

    DTC B2785 is output

    A

    DTC B2785 is not output

    B
    B

    REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY)

    Click here

    A

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

    1. Reconnect the E37 steering lock ECU (steering lock actuator assembly) connector.

    2. Disconnect the E87 ID code box (immobiliser code ECU) connector.

    3. Clear the DTCs.

      Click here

      Body Electrical > Entry&Start > Clear DTCs

    4. Recheck for DTCs.

      Body Electrical > Entry&Start > Trouble Codes

    Result

    Result

    Proceed to

    DTC B2785 is output

    A

    DTC B2785 is not output

    B
    A

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    B

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU)