Line Pressure Solenoid Valve

The line pressure solenoid valve is installed to control valve assembly.

Fig 1: Identifying Line Pressure Solenoid Valve
Courtesy of NISSAN NORTH AMERICA, INC.
The line pressure solenoid valve regulates the oil pump discharge pressure to suit the driving condition in response to a signal transmitted from the TCM.
The line pressure solenoid valve utilizes a linear solenoid valve [N/L (normal low) type].

Fig 2: Current Versus Oil Pressure Graph
Courtesy of NISSAN NORTH AMERICA, INC.
NOTE:
- The principle of the linear solenoid valve utilizes the fact that the force pressing on the valve spool installed inside the coil increases nearly in proportion to the current. This allows it to produce a fluid pressure that is proportional to this pressing force.
- The N/L (normal low) type does not produce hydraulic control when the coil is not energized.