V50 AWD L5-2.5L Turbo VIN 68 B5254T3 (2005)
The differential electronic module (DEM) is secured directly to the coupling unit and forms a single unit with the axial solenoid and control valve. The
differential electronic module (DEM) receives signals from the engine control module (ECM) and the brake control module (BCM) via the control
area network (CAN). The differential electronic module (DEM) uses the sensor signals to control the oil pressure to the multi-plate clutch by adjusting
the axial solenoid. The axial solenoid regulates the control valve constantly using a pulse width modulation (PWM) signal. The oil pressure for the
multi-plate clutch determines the amount of torque which can be transferred to the rear wheels.
Note: If the car has dynamic stability and traction control (DSTC), the required stability control is applied before four wheel drive.
Active On demand Coupling (AOC) has an oil pressure and temperature sensor, which gauge the prevailing temperature and pressure of the hydraulic
fluid. The oil pressure and temperature sensor provide the differential electronic module (DEM) with information about the temperature and pressure.
Four wheel drive is disengaged to protect the coupling unit from damage if the temperature becomes too high, above 105°C The coupling unit is
re-engaged at full function when the temperature falls below 101°C
Mechanical function, overview
