Dtc B2785 Communication Malfunction Between Ecus Connected By Lin

Power Source Network. Land Cruiser. Urj200, 202 Grj200 Vdj200
Networking. Land Cruiser. Urj200, 202 Grj200 Vdj200

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - MASTER SWITCH)

CHECK FOR DTC

CHECK FOR DTC

CHECK FOR DTC

REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH)

CHECK FOR DTC

REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY)

CHECK FOR DTC

REPLACE ID CODE BOX (IMMOBILISER CODE ECU)

CHECK FOR DTC

DTC 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 output when a malfunction in the LIN communication bus between the components related to certification is detected continuously 3 times.

DTC Code
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.
  1. Certification ECU (smart key ECU assembly)
  2. Main body ECU (cowl side junction block LH)
  3. ID code box (immobiliser code ECU)
  4. Steering lock ECU
  5. Harness or connector

WIRING DIAGRAM


Land Cruiser. Urj200, 202 Grj200 Vdj200.Networking.Lin Communication System. Dtc B2785 Communication Malfunction Between Ecus Connected By Lin


INSPECTION PROCEDURE

NOTICE:
When using the intelligent tester with the ignition switch off to troubleshoot:
Connect intelligent tester to the vehicle, and turn a courtesy switch on and off at 1.5 second intervals until communication between the intelligent tester and vehicle begins.
HINT:
When DTC B2785 and B2287 are output simultaneously, perform the troubleshooting for DTC B2785 first.
1.CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - MASTER SWITCH)


    Land Cruiser. Urj200, 202 Grj200 Vdj200.Networking.Lin Communication System. Dtc B2785 Communication Malfunction Between Ecus Connected By Lin

  1. Disconnect the 2D and E29 ECU connectors.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    E29-10 (LIN) - 2D-20 (LIN1)
    		Always
    		Below 1 Ω
    E29-10 (LIN) - Body ground
    		Always
    		10 kΩ or higher

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    E29-10 (LIN) - Body ground
    		Always
    		Below 1 V


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


2.CHECK FOR DTC

  1. Reconnect the E26 and E29 ECU connectors.

  1. Reconnect the E28 box connector.

  1. Clear the DTC (Click here).

  1. Recheck for DTCs.

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


B
Go to step 5
A


3.CHECK FOR DTC

  1. Reconnect the 2D ECU connector.

  1. Disconnect the E26 ECU connector.

  1. Clear the DTC (Click here).

  1. Recheck for DTCs.

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


B
Go to step 7
A


4.CHECK FOR DTC

  1. Reconnect the E26 ECU connector.

  1. Disconnect the E28 box ECU connector.

  1. Clear the DTC (Click here).

  1. Recheck for DTCs.

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


B
Go to step 9
A

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

5.REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH)

  1. Temporarily replace the main body ECU (cowl side junction block LH) with a new or normally functioning one.

  1. Clear the DTC (Click here).


NEXT


6.CHECK FOR DTC

  1. Recheck for DTCs.

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


B
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
A

END (MAIN BODY ECU IS DEFECTIVE)

7.REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY)

  1. Temporarily replace the steering lock ECU with a new or normally functioning one (Click here).

  1. Clear the DTC (Click here).


NEXT


8.CHECK FOR DTC

  1. Recheck for DTCs.

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


B
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
A

END (STEERING LOCK ECU IS DEFECTIVE)

9.REPLACE ID CODE BOX (IMMOBILISER CODE ECU)

  1. Temporarily replace the ID code box immobiliser code ECU with a new or normally functioning one.

  1. Clear the DTC (Click here).


NEXT


10.CHECK FOR DTC

  1. Recheck for DTCs (Click here).

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


B
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
A

END (ID CODE BOX IS DEFECTIVE)