Up to 08/2009

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 key.
* If the steering lock ECU (steering lock actuator assembly) is replaced, register the ECU code.
* If the ID code box (immobiliser code ECU) is replaced, register the ECU code and ECU communication ID.
* When using the Techstream to troubleshoot with the engine 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 F58, F8, F45 and F37 connectors.





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

Standard Resistance:





Text in Illustration





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 F58, F8 and F45 connectors.

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

(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 F37 connector.

(b) Disconnect the F8 connector.

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

(d) Recheck for DTCs.

Result:





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

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

(a) Reconnect the F8 connector.

(b) Disconnect the F45 connector.

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

(d) Recheck for DTCs.

Result:





B -- REPLACE ID CODE BOX (IMMOBILISER CODE ECU)

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