Control Module

Fig 1: Active On Demand Coupling Control Module

Courtesy of VOLVO CARS CORPORATION

The differential electronic module (DEM) is secured directly to the coupling unit housing and forms a single unit with the axial solenoid. The axial solenoid controls the control valve.

The differential electronic module (DEM) receives signals from the engine control module (ECM), the central electronic module (CEM) and the brake control module (BCM) via the high speed side of the control area network (CAN). The differential electronic module (DEM) uses these signals to determine the oil pressure required for the multi-plate clutch in the coupling unit. The oil pressure for the multi-plate clutch determines the amount of torque which can be transferred to the rear wheels.

Four wheel drive is not available if there is a fault in the differential electronic module (DEM).