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HOMESERVICE MANUALSSUBARU2016LEGACY 2.5IREPAIR AND DIAGNOSISACCESSORIES & EQUIPMENTCOMMUNICATION DEVICESLAN COMMUNICATION SYSTEM (DIAGNOSTICS)DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)DTC U0122 LOST COMMUNICATION WITH VEHICLE DYNAMICS CONTROL MODULETROUBLE SYMPTOM
2016 Subaru Legacy 2.5i

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

2016 Subaru Legacy 2.5iSECTION Trouble Symptom

ABS warning light and VDC warning light illuminate.

DIAGNOSTICS PROCEDURE

Step Check Yes No
1 CHECK PERFORMING OF BASIC DIAGNOSTIC PROCEDURE.  Was the basic diagnostic procedure performed up to STEP 8? Go to step 2  . Perform the basic diagnostic procedure. < Ref. to BASIC DIAGNOSTIC PROCEDURE . >
2 CHECK DTC. 
Check the displayed DTC.		 Are DTCs other than U*** displayed? Perform the diagnosis according to DTC. Go to step 3  .
3 CHECK DTC. 
Check the displayed DTC.		 Is U0122 a current malfunction? Go to step 4  . Go to step 8  .
4 CHECK DTC. 
  1. Check CAN communication circuit. < Ref. to CAN COMMUNICATION CIRCUIT CHECK . >
  2. Read the DTC using Subaru Select Monitor.
 Is U0122 a current malfunction? Go to step 5  . Go to step 8  .
5 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 control module. < Ref. to VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U) . > Go to step 6  .
6 REPLACE MODULE. 
  1. Replace the VDC control module.
  2. Read the DTC using Subaru Select Monitor.
 Is U0122 a current malfunction? Go to step 7  . System is normal.
7 CHECK MODULE. 
  1. Reinstall the VDC control module.
  2. Replace the module that the DTC has been detected.
  3. Read the DTC using Subaru Select Monitor.
 Is U0122 a current malfunction? Replace the VDC control module. < Ref. to VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U) . > System is normal.
8 CHECK HARNESS. 
  1. Shake the harness, and check for poor contact.
  2. 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 9  .
9 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.
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

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  • • You are missing required tools, torque specs, or safe lifting equipment.
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