Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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.
- Hill hold does not function.
- EyeSight does not operate.
Wiring diagram:
Vehicle dynamics control system Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV))>VEHICLE DYNAMICS CONTROL SYSTEM .
- CHECK VDCCM AND H/U INPUT VOLTAGE
.
- Turn the ignition switch to OFF.
- Disconnect the connector from the VDCCM and H/U.
- Run the engine at idle.
- Measure the voltage between VDCCM and 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.
- CHECK VDCCM AND H/U INPUT VOLTAGE
.
Calculate the voltage difference measured in step 1.
- (B310) No. 30 (+) - Chassis ground (-):
- (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.
- CHECK VDCCM AND H/U GROUND CIRCUIT (CHECK FOR OPEN CIRCUIT)
.
- Turn the ignition switch to OFF.
- Measure the resistance between VDCCM and 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 and H/U ground harness.
- CHECK POOR CONTACT OF CONNECTORS
.
Is there poor contact of connector between generator, battery and VDCCM and H/U?
Yes: Repair the connector.
No: Go to 5.
- CHECK VDCCM AND H/U
.
- Connect all connectors.
- Using the Subaru Select Monitor, perform the clear memory of [Brake Control]. Ref. to COMMON (DIAG)>CLEAR MEMORY .
- Execute the inspection mode. Ref. to BRAKE CONTROL (DIAGNOSTICS) (HEV)>INSPECTION MODE .
- Read the DTC of [Brake Control] using the Subaru Select Monitor. Ref. to BRAKE CONTROL (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .
Is the same DTC displayed?
Yes: Replace the VDCCM and H/U. Ref. to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U) .
No: Go to 6.
- CHECK DETECTION OF OTHER DTCS FOR VDC
.
Read the DTC of [Brake Control] using the Subaru Select Monitor. Ref. to BRAKE CONTROL (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .
Is any other DTC displayed?
Yes: Perform the diagnosis according to the DTC. Ref. to BRAKE CONTROL (DIAGNOSTICS) (HEV)>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.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.