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Home >> Volvo >> 2001 >> V70 XC >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Alarm System, Control Modules, Engine Management Systems - Design And Function >> Active On Demand Coupling (AOC) (2003-2004) >> System overview >> Signals
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System overview: Signals

The chart below summarizes the input signals to and output signals from the differential electronic module (DEM). The following illustration displays the same information with the Volvo component designations.

Input signals Output signals
Directly connected:  Directly connected:  (power supply unless otherwise stated)
  • Oil pressure and temperature sensor  .
  • Electrical feed pump 
  • Axial solenoid  - pulse width modulated (PWM) signal.
Via Controller Area Network (CAN) communication:  Via Controller Area Network (CAN) communication: 
  • Central electronic module (CEM)  (4/56), status of the parking brake switch, ignition key position and back-up (reverse) signal
  • Brake control module (BCM)  (4/16), the wheel speed from the wheel rotation sensor and the status signal (to open the coupling during stability control)
  • Engine control module (ECM)  (4/46), provides data about engine speed (RPM), torque, accelerator pedal (AP) position and the status of the stop lamp switch.
  • Brake control module (BCM)  (4/16), status of the coupling.
Fig 1: Input Signals To And Output Signals From Differential Electronic Module
GLL106595Courtesy of VOLVO CARS OF NORTH AMERICA.