B2785

NETWORKING: LIN COMMUNICATION SYSTEM: B2785: Communication Malfunction between ECUs Connected by LIN
B2785 - Communication Malfunction between ECUs Connected by LIN

DESCRIPTION

The certification ECU 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.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
* When using the Techstream with the engine switch off to troubleshoot:
Connect the Techstream to the vehicle and turn a courtesy light switch on and off at 1.5 second intervals until communication between the Techstream and vehicle begins.
* Before replacing the certification ECU, ID code box or steering lock ECU, refer to the engine immobiliser system Engine Immobilizer System.

HINT
* When DTC B2785 and a LIN communication stop DTC are output simultaneously, first perform troubleshooting for DTC B2785. Then perform troubleshooting for the LIN communication stop DTC.
* When DTC B2785 and B2287 are output simultaneously, perform troubleshooting for DTC B2785 first.

PROCEDURE

1. CLEAR DTC

(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

NEXT -- Continue to next step.

2. CHECK FOR DTC

(a) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B2785 is not output.

NG -- CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - POWER MANAGEMENT CONTROL ECU)

OK -- USE SIMULATION METHOD TO CHECK Electronic Circuit Inspection Procedure

3. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - POWER MANAGEMENT CONTROL ECU)

(a) Disconnect the G26 certification ECU connector.

(b) Disconnect the G39 power management control ECU connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. CLEAR DTC

(a) Connect the G26 certification ECU connector.

(b) Disconnect the G39 power management control ECU connector.

(c) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

NEXT -- Continue to next step.

5. CHECK FOR DTC

(a) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

Result





B -- REPLACE POWER MANAGEMENT CONTROL ECU Removal
A -- Continue to next step.

6. CLEAR DTC

(a) Connect the G39 power management control ECU connector.

(b) Disconnect the G23 steering lock actuator assembly (steering lock ECU) connector.

(c) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

NEXT -- Continue to next step.

7. CHECK FOR DTC

(a) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

Result





B -- REPLACE STEERING LOCK ACTUATOR ASSEMBLY Disassembly
A -- Continue to next step.

8. CLEAR DTC

(a) Connect the G23 steering lock actuator assembly (steering lock ECU) connector.

(b) Disconnect the G25 ID code box connector.

(c) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

NEXT -- Continue to next step.

9. CHECK FOR DTC

(a) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

Result





B -- REPLACE ID CODE BOX Removal

A -- REPLACE CERTIFICATION ECU Removal