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. DTC Detection Condition Trouble Area
B2785

  • 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)

  • Power management control ECU

  • Steering lock ECU (steering lock actuator assembly)

  • Wire harness or connector

WIRING DIAGRAM

A011WAUE07

INSPECTION PROCEDURE

Note

  • If the certification ECU (smart key ECU assembly) is replaced, register the keys Click here.

  • If the steering lock ECU (steering lock actuator assembly) is replaced, register the ECU code Click here.

  • When using the Techstream to troubleshoot with the power switch off:

    Connect the Techstream to the DLC3, and turn the courtesy switch on and off at 1.5-second intervals until communication between the Techstream and vehicle begins.

PROCEDURE

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

    1. Disconnect the I24 steering lock ECU (steering lock actuator assembly) connector.

    2. Disconnect the I87certification ECU (smart key ECU assembly) connector.

    3. Disconnect the I4 power management control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I87-12 (LIN) - I4-11 (LIN2) Always Below 1 Ω
      I87-12 (LIN) - I24-5 (LIN) Always Below 1 Ω
      I4-11 (LIN2) - Body ground Always 10 kΩ or higher
      I24-5 (LIN) - Body ground Always 10 kΩ or higher
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK DTC OUTPUT (STEERING LOCK ECU ASSEMBLY)

    1. Reconnect the I87certification ECU (smart key ECU assembly) connector.

    2. Reconnect the I4 power management control ECU connector.

    3. Clear the DTC Click here.

    4. Recheck for DTCs.

      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 (POWER MANAGEMENT CONTROL ECU)

    1. Reconnect the I24 steering lock ECU (steering lock actuator assembly) connector.

    2. Disconnect the I4 power management control ECU connector.

    3. Clear the DTC Click here.

    4. Recheck 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

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Click here