DTC U0140 Lost Communication With Body Control Module: Wiring Diagram

CAN communication system. See appropriate SYSTEM WIRING DIAGRAM article.

Fig 1: CAN Communication System - Wiring Diagram

G08585509

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK DTC. Check the displayed DTC.	Are DTCs other than U*** displayed?	Perform the diagnosis according to DTC.	Go to step 2 .
2 CHECK DTC. Check the displayed DTC.	Is U0140 a current malfunction?	Go to step 3 .	Go to step 7 .
3 CHECK DTC. Check CAN communication circuit. Refer to BUS "A" (MAIN-CAN) . Read the DTC using Subaru Select Monitor.	Is U0140 a current malfunction?	Go to step 4 .	Go to step 7 .
4 CHECK DTC. Using the Subaru Select Monitor, read DTC of all the systems.	Is the body integrated data no-receive detected in several modules?	Replace the body integrated unit. Refer to BODY INTEGRATED UNIT .	Go to step 5 .
5 REPLACE MODULE. Replace the body integrated unit. Read the DTC using Subaru Select Monitor.	Is U0140 a current malfunction?	Go to step 6 .	System is normal.
6 CHECK MODULE. Reinstall the body integrated unit. Replace the module that the DTC has been detected. Read the DTC using Subaru Select Monitor.	Is U0140 a current malfunction?	Replace the body integrated unit. Refer to BODY INTEGRATED UNIT .	System is normal.
7 CHECK HARNESS. Shake the harness, and check for poor contact. Read the DTC using Subaru Select Monitor.	Is U0140 a current malfunction?	Repair the poor contact of harness, or replace the harness.	Go to step 8 .
8 CHECK CONNECTOR. Check the connector used for high speed CAN for poor contact.	Is there poor contact of connector?	Repair the connector that has poor contact, or replace harness.	It is possible that temporary poor communication occurs. Delete the DTC.