Electric Controlled Coupling

The 4WD control unit supplies command current to electric controlled coupling (4WD solenoid).
The control clutch is engaged by electromagnet and torque is detected in control clutch.
The cam operates in response to control clutch torque and applies pressure to main clutch.
The main clutch transmits torque to front wheels according to pressing power.

Fig 1: Identifying Electric Controlled Coupling Components
Courtesy of NISSAN NORTH AMERICA, INC.
- Transmission torque to the rear wheels is determined according to command current.
  
  Fig 2: Electric Controlled Coupling Current And Torque Characteristics Graph
  Courtesy of NISSAN NORTH AMERICA, INC.