Control Module

Fig 1: Identifying Differential Electronic Module (DEM)

Courtesy of VOLVO CARS CORPORATION

Differential Electronic Module (DEM) is directly secured onto the clutch unit housing and together with the axial solenoid constitutes one unit. The axial solenoid controls the control valve.

The Differential Electronic Module (DEM) receives signals via the Controller Area Network (CAN) from: 

• Engine Control Module (ECM)
• Central Electronic Module (CEM)
• Brake Control Module (BCM)
• Driver Information Module (DIM).

Conducted by these signals, the Differential Electronic Module (DEM) determines how high the oil pressure to the clutch unit should be. The oil pressure to the clutch driven plates is decisive for how much torque can be transferred to the rear wheels.

Four-wheel drive does not function in the event of a fault in the Differential Electronic Module (DEM).