Dtc B2785 Communication Malfunction Between Ecus Connected By Lin

Communication System. Camry. Acv40 Gsv40
Multiplex Communication. Camry. Acv40 Gsv40

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - EACH ECU)

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

CHECK DTC OUTPUT (MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK))

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

DTC 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 Code
DTC Detection Condition
Trouble Area
B2785
  1. Errors in LIN communication between ECUs or an open or short in communication lines
  2. LIN communication from the certification ECU (smart key ECU assembly) detects errors in communication 3 times in a row
  1. Certification ECU (Smart key ECU assembly)
  2. Main body ECU (Instrument panel junction block)
  3. Steering lock ECU (Steering lock actuator assembly)
  4. ID code box (Immobiliser code ECU)
  5. Wire harness or connector

WIRING DIAGRAM


Camry. Acv40 Gsv40.Multiplex Communication.Lin Communication System. Dtc B2785 Communication Malfunction Between Ecus Connected By Lin


INSPECTION PROCEDURE

NOTICE:
  1. If the certification ECU (smart key ECU assembly) is replaced, register the key.
  2. If the steering lock ECU (steering lock actuator assembly) is replaced, register the ECU code.
  3. If the ID code box (immobiliser code ECU) is replaced, register the ECU code and ECU communication ID.
  4. When using the intelligent tester to troubleshoot with the engine switch off:
    Connect the intelligent tester to the DLC3, and turn the courtesy switch on and off at 1.5-second intervals until communication between the intelligent tester and vehicle begins.
1.CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - EACH ECU)


  1. Disconnect the E74, E68 and E69 ECU connectors.


    Camry. Acv40 Gsv40.Multiplex Communication.Lin Communication System. Dtc B2785 Communication Malfunction Between Ecus Connected By Lin

  1. Disconnect the IR junction block connector.

  1. Measure the resistance and voltage according to the value(s) in the table below.

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    E74-10 (LIN) - E69-5 (LIN)
    		Always
    		Below 1 Ω
    E74-10 (LIN) - IR-9 (LIN1)
    		Always
    		Below 1 Ω
    E74-10 (LIN) - E68-3 (LIN1)
    		Always
    		Below 1 Ω
    E74-10 (LIN) - Body ground
    		Always
    		10 kΩ or higher
    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    E74-10 (LIN) - Body ground
    		Always
    		Below 1 V


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


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

  1. Reconnect the E74 and E68 ECU connectors.

  1. Reconnect the IR junction block connector.

  1. Clear the DTC (CAMRY_ACV40 RM000002XHS00KX.html).

  1. 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) (CAMRY_ACV40 RM000000WAD03BX.html)
A


3.CHECK DTC OUTPUT (MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK))

  1. Reconnect the E69 ECU connector.

  1. Disconnect the IR junction block connector.

  1. Clear the DTC (CAMRY_ACV40 RM000002XHS00KX.html).

  1. Recheck for DTCs.

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


B
REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)
A


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

  1. Reconnect the IR junction block connector.

  1. Disconnect the E68 ECU connector.

  1. Clear the DTC (CAMRY_ACV40 RM000002XHS00KX.html).

  1. Recheck for DTCs.

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


B
REPLACE ID CODE BOX (IMMOBILISER CODE ECU)
A

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)