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Home >> Volvo >> 2004 >> XC70 >> Repair and Diagnosis (Single Page) >> External Pages >> Different car >> Section 9 (Alarm System, Control Modules, Engine Management Systems - Design And Function) >> Active On Demand Coupling (AOC) (2003-2004) >> System overview >> Coupling unit and control module
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Coupling unit and control module

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2007 Volvo V70, 2006 Volvo V70, 2005 Volvo V70, 2004 Volvo V70, and 2003 Volvo V70. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Coupling Unit And Control Module
GLL107816Courtesy of VOLVO CARS OF NORTH AMERICA.

The hydraulic section consists of 1-5, the mechanical section consists of 6-10 and the electronic section consists of 11-13.

  1. Pressure valves
  2. Accumulator
  3. Oil filter
  4. Annular pistons
  5. Control valve/axial solenoid
  6. Input shaft
  7. Inner and outer wet multi-plate clutch
  8. Inner connection hub with sinusoidal cam disc
  9. Rollers with annular pistons
  10. Output shaft
  11. Electrical feed pump
  12. Differential electronic module (DEM)
  13. Oil pressure and temperature sensor.

The differential electronic module (DEM) is integrated in the coupling unit.

The differential electronic module (DEM) communicates with other control modules using controller area network (CAN) communication.

There are internal diagnostics for the control module.