DTC C1511: Valve Relay

DTC detecting condition: 

A fault is detected if valve relay drive voltage failure is detected.

Trouble symptom: 

• ABS does not operate.
• EBD does not operate.
• VDC does not operate.
• AVH does not function.
• EyeSight does not operate.

Wiring diagram: 

Vehicle dynamics control system Ref. to WIRING SYSTEM>VEHICLE DYNAMICS CONTROL SYSTEM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK VDCCM & H/U INPUT VOLTAGE. 
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from the VDCCM & H/U.
   3. Run the engine at idle.
   4. Measure the voltage between VDCCM & H/U connector and chassis ground.

      Connector and terminal 

      (B310) No. 30 (+) - Chassis ground (-):

      (B310) No. 35 (+) - Chassis ground (-):

   Is the voltage 10 - 15 V?

   Yes  : Go to  2.

   No  : Repair the power supply circuit.

2. CHECK VDCCM & H/U INPUT VOLTAGE. 

   Calculate the voltage difference measured in step 1.

   A: (B310) No. 30 (+) - Chassis ground (-):

   B: (B310) No. 35 (+) - Chassis ground (-):

   Is the voltage difference between A and B 2 V or more?

   Yes  : Repair the power supply circuit.

   No  : Go to  3.

3. CHECK VDCCM & H/U GROUND CIRCUIT (CHECK FOR OPEN CIRCUIT). 
   1. Turn the ignition switch to OFF.
   2. Measure the resistance between VDCCM & H/U connector and chassis ground.

      Connector and terminal 

      (B310) No. 14 - Chassis ground:

   Is the resistance less than 10 Ω?

   Yes  : Go to  4.

   No  : Repair the VDCCM & H/U ground harness.

4. CHECK POOR CONTACT OF CONNECTORS. 

   Is there poor contact of connector between generator, battery and VDCCM & H/U?

   Yes  : Repair the connector.

   No  : Go to  5.

5. CHECK VDCCM & H/U. 
   1. Connect all connectors.
   2. Using the Subaru Select Monitor, perform the clear memory. Ref. to COMMON (diag)>CLEAR MEMORY .
   3. Execute the inspection mode. Ref. to BRAKE CONTROL (DIAGNOSTICS)>INSPECTION MODE .
   4. Read the DTC using Subaru Select Monitor. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is the same DTC displayed?

   Yes  : Replace the VDCCM & H/U. Ref. 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. 

   Read the DTC using Subaru Select Monitor. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is any other DTC displayed?

   Yes  : Perform the diagnosis according to DTC. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST .

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