DTC C1422: VDC Interruption For Engine Convenience

DTC detecting condition: 

A fault is detected if engine control prohibition flag from ECM is received.

Trouble symptom: 

• VDC does not operate.
• Hill start assist does not operate. (Models without EyeSight)
• AVH does not function. (Models with EyeSight)
  NOTE: Warning lights go off if the cooperation control of ECM returns.

1. CHECK COOPERATION CONTROL FEASIBILITY OF ECM USING SUBARU SELECT MONITOR. 
   1. Start the engine, and run the engine at idle approximately 5 minutes.
   2. Using the Subaru Select Monitor, select "Data monitor". Refer to VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)>SUBARU SELECT MONITOR>OPERATION>READ CURRENT DATA .
   3. Check the «E/G Torque Down Control Stop Flag» displayed on screen.

   Does the «E/G Torque Down Control Stop Flag» indicate "1"?

   Yes:  Go to  4.

   No:  Go to  2.

2. CHECK WARNING LIGHT. 

   Check whether the VDC warning light illuminates after driving for 1 minute or more at a speed of 10 km/h (6 MPH) or more.

   Does the VDC warning light illuminate?

   Yes:  Go to  3.

   No:  VDC is normal. Perform the Clear Memory Mode. Refer to VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)>CLEAR MEMORY MODE .

   NOTE: DTC may be recorded if cranking is performed during driving.
3. CHECK POOR CONTACT OF CONNECTORS. 

   Is there poor contact of ECM connector?

   Yes:  Repair the connector.

   No:  Go to  4.

4. CHECK DTC OF ECM. 

   Read the DTC relating the ECM using the Subaru Select Monitor. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>READ DIAGNOSTIC TROUBLE CODE (DTC) . Refer to ENGINE (DIAGNOSTICS) (STI)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

   Are any DTCs displayed?

   Yes:  Perform the diagnosis according to DTC. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC) . Refer to ENGINE (DIAGNOSTICS) (STI)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .

   No:  Go to  5.

5. CHECK VDC Control Module & H/U. 
   1. Connect all connectors.
   2. Perform the Clear Memory Mode. Refer to VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)>CLEAR MEMORY MODE .
   3. Perform the Inspection Mode. Refer to VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)>INSPECTION MODE .
   4. Read the DTC. Refer to VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

   Is the same DTC displayed?

   Yes:  Replace the VDC Control Module & H/U. Refer to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U) .

   No:  Go to  6.

6. CHECK DETECTION OF OTHER DTCS FOR VDC. 

   Refer to VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

   Is any other DTC displayed?

   Yes:  Perform the diagnosis according to DTC. Refer to VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .

   No:  Currently, it is normal. There may have been a temporary poor contact in the harness and connector or a temporary noise interference.