Functional description: Notes

The characteristic map control influences the oil pressure in the control oil chamber. Two valves are involved in the characteristic map control:

• Oil pressure regulating valve
• Pressure limiting valve as fallback level

The oil pressure control valve can influence the oil pressure in the control oil chamber steplessly. The further the oil pressure is reduced, the more volume the volume-flow-controlled oil pump delivers. The main spring in the volumetric-flow-controlled oil pump that affects the slider is softer than in conventional systems. The slider is easier to move to a centered position, which means that the volume-flow-controlled oil pump adjusts to minimum delivery even with slight oil pressure in the control oil chamber. This reduces the pressure ratio in the oil circuit, which in turn means less energy to drive the volumetric-flow-controlled oil pump.

Fig 1: Identifying Oil Pressure Regulating Valve And Two Pin Plug Connection

Courtesy of BMW OF NORTH AMERICA, INC.

The oil pressure control valve can influence the oil pressure in the controllable oil chamber steplessly. In the case of decreasing oil pressure, the volume-flow-controlled oil pump delivers more volume. The main spring in the volumetric-flow-controlled oil pump that affects the slider is softer than in conventional systems. The slider is easier to move to a centered position, which means that the volume-flow-controlled oil pump adjusts to minimum delivery even with slight oil pressure in the controllable oil chamber. This reduces the pressure ratio in the oil circuit, which in turn means less energy to drive the volumetric-flow-controlled oil pump. The use of characteristic map control for the volumetric-flow-controlled oil pump enables oil supply in line with requirements and a reduction in the average pressure level in the oil circuit. The oil pressure control valve enables the engine control to individually control the fuel delivery rate.

Fig 1: Identifying Oil Pressure Regulating Valve And Two-Pin Plug Connection

Courtesy of BMW OF NORTH AMERICA, INC.