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)

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) (W/O 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) (W/O 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 (VDC Control Module & 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.