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 (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.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
* If the certification ECU (smart key ECU assembly) is replaced, register the keys Engine Immobilizer System.
* If the steering lock ECU (steering lock actuator assembly) is replaced, register the ECU code Engine Immobilizer System.
* 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)

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

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

(c) Disconnect the I4 power management control ECU connector.

(d) 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.

2. CHECK DTC OUTPUT (STEERING LOCK ECU ASSEMBLY)

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

(b) Reconnect the I4 power management control ECU connector.

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

(d) Recheck for DTCs.

Result:





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

3. CHECK DTC OUTPUT (POWER MANAGEMENT CONTROL ECU)

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

(b) Disconnect the I4 power management control ECU connector.

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

(d) Recheck for DTCs.

Result:





B -- REPLACE POWER MANAGEMENT CONTROL ECU Removal

A -- REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Removal