Control Valve, Engine Oil Pump

Courtesy of VOLVO CARS CORPORATION

The oil pump control valve controls displacement to the oil pump and thus controls the oil pressure in the engine.

The valve, which is a proportional valve, regulates the oil flow through the valve via electromagnetism generated by an electric control signal from the Engine Control Module (ECM).

The oil is routed into the pump housing where the oil pump is located in a rotating cradle. The cradle divides the pump housing into two chambers and the flow from the control valve generates a pressure on one side of the cradle. Pressure aids in turning the cradle, which is otherwise return sprung to the mechanical limit position. When the cradle turns, the size of the pump volume changes, which affects the flow and the oil pressure in the engine.

The oil pump ensures that the pressure in the engine oil is maintained and that all engine parts are supplied with oil. The pump is driven mechanically when the engine is running, at a pump speed that varies with engine speed. As the oil pressure can be continuously demand controlled, one can compensate for specific operating conditions, thus minimizing power output and contributing to reduced component wear.

The reset valve is powered with 12V through the relay/fusebox engine compartment and grounded (signal) in the control module.

The reset valve can be diagnosed by the Engine Control Module (ECM) and the current deployment can be read off.