DTC U0122 Lost Communication With Vehicle Dynamics Control Module: Trouble Symptom

ABS warning light and VDC warning light illuminate.

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 U0122 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 U0122 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 VDC data no-receive detected in several modules?	Replace the VDC CM. Refer to VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM&H/U) .	Go to step 5 .
5 REPLACE MODULE. Replace the VDC CM. Read the DTC using Subaru Select Monitor.	Is U0122 a current malfunction?	Go to step 6 .	System is normal.
6 CHECK MODULE. Reinstall the VDC CM. Replace the module that the DTC has been detected. Read the DTC using Subaru Select Monitor.	Is U0122 a current malfunction?	Replace the VDC CM. Refer to VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM&H/U) .	System is normal.
7 CHECK HARNESS. Shake the harness, and check for poor contact. Read the DTC using Subaru Select Monitor.	Is U0122 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.