DTC C0051 Valve Relay: Wiring Diagram

WARNING: This page is about a different car, the 2012 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Valve Relay Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE CHART

Step	Check	Yes	No
1 CHECK VDCCM&H/U INPUT VOLTAGE. Turn the ignition switch to OFF. Disconnect the connector from the VDCCM&H/U. Run the engine at idle. Measure the voltage between VDCCM&H/U connector and chassis ground. Connector & terminal (B310) No. 28 (+) - Chassis ground (-): (B310) No. 24 (+) - Chassis ground (-):	Is the voltage 10 - 15 V?	Go to step 2.	Repair the power supply circuit.
2 CHECK VDCCM&H/U INPUT VOLTAGE. Calculate the voltage difference measured in step 1. A: (B310) No. 28 (+) - Chassis ground (-): B: (B310) No. 24 (+) - Chassis ground (-):	Is the voltage difference between A and B 2 V or more?	Repair the power supply circuit.	Go to step 3 .
3 CHECK VDCCM&H/U GROUND CIRCUIT. Turn the ignition switch to OFF. Measure the resistance between VDCCM&H/U connector and chassis ground. Connector & terminal (B310) No. 25 - Chassis ground:	Is the resistance less than 10 Ω?	Go to step 4.	Repair the VDCCM&H/U ground harness.
4 CHECK VDCCM&H/U VALVE RELAY. Measure the resistance between VDCCM&H/U connector terminals. Connector & terminal (B310) No. 24 - (B310) No. 25:	Is the resistance 1 MΩ or more?	Go to step 5.	Replace the VDCCM&H/U. < Ref. to VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM&H/U) . >
5 CHECK POOR CONTACT OF CONNECTORS.	Is there poor contact of connector between generator, battery and VDCCM&H/U?	Repair the connector.	Go to step 6 .
6 CHECK VDCCM&H/U. Connect all connectors. Clear the memory. < Ref. to CLEAR MEMORY MODE . > Perform the Inspection Mode. < Ref. to INSPECTION MODE . > Read the DTC.	Is the same DTC displayed?	Replace the VDCCM only. < Ref. to REPLACEMENT , VDC Control Module and Hydraulic Control Unit (VDCCM&H/U). >	Go to step 7 .
7 CHECK OTHER DTC DETECTION.	Is any other DTC displayed?	Perform the diagnosis according to DTC. < Ref. to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) . >	Temporary poor contact occurs.