Control Module

Fig 1: Differential Electronic 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 control valve/axial solenoid. The control module and the control valve/axial solenoid are calibrated together at the factory and can therefore only be replaced together.

Via the controller area network (CAN), the differential electronic module (DEM) receives signals from:

• engine control module (ECM)
• central electronic module (CEM)
• brake system 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).