Principles of Operation

Differential Electronic Module (DEM)


Principles of Operation

Differential Electronic Module (DEM) and Active On-Demand Coupling
The main role of active on-demand coupling and the Differential Electronic Module (DEM) is to regulate the 4WD function by distributing torque between the front and rear axles. The system consists of a coupling that combines mechanical, hydraulic and electronic sections. The coupling unit is attached to the rear axle, between the differential gear and the driveshaft. The mechanical and hydraulic sections are driven by the driveshaft. Active On-Demand Coupling (AOC) has the following characteristics:
^ Permanent AWD with electronic control of torque transfer front to rear
^ Similar to 4WD operation
^ No driveline wind-up during slow speed maneuvers or parking

The system is not sensitive to size differences between the 4 road tires (when driving with a spare wheel, for example). The system is not sensitive to being towed with one axle raised.