B2785

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

DTC B2785 - Communication Malfunction between ECUs Connected by LIN

DESCRIPTION

This DTC is stored when LIN communication from the certification ECU stops for a certain amount of time.





WIRING DIAGRAM





INSPECTION PROCEDURE
NOTICE:
- If the certification ECU (smart key ECU assembly) is replaced, register the key.
- If the steering lock ECU (steering lock actuator assembly) is replaced, register the ECU code.
- When using the Techstream to troubleshoot with the ignition 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 D25, D43 and D17 ECU connectors.





Text in Illustration





(b) Measure the resistance and voltage according to the value(s) in the table below.
Standard Resistance:





Standard Voltage:






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

2. CHECK DTC OUTPUT (STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY))
(a) Reconnect the D25 and D43 ECU connectors.
(b) Clear the DTC Initial Inspection and Diagnostic Overview.
(c) Recheck for DTCs.
Result:





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

3. CHECK DTC OUTPUT (POWER MANAGEMENT CONTROL ECU)
(a) Reconnect the D17 ECU connector.
(b) Disconnect the D43 ECU connector.
(c) Clear the DTC Initial Inspection and Diagnostic Overview.
(d) Recheck for DTCs.
Result:





B -- REPLACE POWER MANAGEMENT CONTROL ECU
A -- REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)