Rear door control unit, component description - GF72.29-P-6020LE

MODEL 221.0 /1 as of model year 09 /YoM 08 

Location 

the left and right rear door control units are located behind the door paneling of the left and right rear door.

Task 

The rear door control units have the following tasks:

• Reading in of sensors, pickups and signals 
• Evaluation of input factors 
• Controlling function sequences 
• Actuation of components 

Reading in of sensors, pickups and signals 

The input factors are read in via the following connections:

• Direct line 
• Rear door LIN 
• Interior CAN 

Direct line 

The following signals are read in via a direct line:

• by the left rear door control unit:
  • Circuit 30
  • Circuit 58d

    Left rear rotary tumbler switch (A85/3s1)

  • Right rear drive lock pawl switch (A85/3s2)

    (with code (883) Power closing for doors and trunk lid)

  • Left rear drive lock pawl switch (A85/3s3)

    (with code (883) Power closing for doors and trunk lid)

  • Hall sensor for left rear power window motor (M10/5)
  • Hall sensor for left rear side roller sun blind motor (M24/5) (with code (297) Roller sun blinds in rear doors)
  • Left rear power window switch (S21/3)
• by right rear door control unit:
  • Circuit 30
  • Circuit 58d

    Right rear rotary tumbler switch (A85/4s1)

  • Right rear drive lock pawl switch (A85/4s2)

    (with code (883) Power closing for doors and trunk lid)

  • Right rear safety limit switch (A85/4s3)

    (with code (883) Power closing for doors and trunk lid)

  • Hall sensor for right rear power window motor (M10/6)
  • Hall sensor for right rear roller sun blind motor (M24/6) (with code (297) Roller sun blinds in rear doors)
  • Right rear power window switch (S21/4)

Rear door LIN 

The following switches are in via the rear door LIN:

• to the left rear door control unit:
  • Left rear door power window/roller blind switch group (S21/21) (with code (297) Roller sun blinds in rear doors and with code (540) Electric roller sun blind for rear window and with code (413) Panoramic glass sunroof with top sliding roof and with code (414) Electric glass tilting/sliding roof)
  • Left rear seat operation switch group (S55/1) (with code (223) Bench seat in rear with electrically adjustable outer seats with PRE-SAFE positioning function for outer seats and outer head restraints or with code (276) Memory in rear or with code (402) Rear comfort seat including seat heater and seat ventilation or with code (872) Electric seat heater for left and right rear seat)
  • Head restraint adjustment switch (S55/1s1)
  • Seat cushion inclination switch (S55/1s2)
  • Fore/aft adjustment switch (S55/1s3)
  • Backrest switch (S55/1s5)
  • Memory switch (S55/1s6)
  • Memory 1 switch (S55/1s7)
  • Memory 2 switch (S55/1s8)
  • Memory 3 switch (S55/1s9)
  • Front or rear seat adjustment selection switch (S55/1s10)
  • Seat ventilation switch (S55/1s11)
  • Seat heater switch (S55/1s12)
• to right rear door control unit:
  • Right rear door power window/roller blind switch group (S21/22) (with code (297) Roller sun blinds in rear doors and with code (540) Electric roller sun blind for rear window and with code (413) Panoramic glass sunroof with top sliding roof and with code (414) Electric glass tilting/sliding roof)
  • Right rear seat operation switch group (S55/2) (with code (223) Bench seat in rear with electrically adjustable outer seats with PRE-SAFE positioning function for outer seats and outer head restraints or with code (276) Memory in rear or with code (402) Rear comfort seat including seat heater and seat ventilation or with code (872) Electric seat heater for left and right rear seat)
  • Head restraint adjustment switch (S55/2s1)
  • Seat cushion inclination switch (S55/2s2)
  • Fore/aft adjustment switch (S55/2s3)
  • Backrest switch (S55/2s5)
  • Memory switch (S55/2s6)
  • Memory 1 switch (S55/2s7)
  • Memory 2 switch (S55/2s8)
  • Memory 3 switch (S55/2s9)
  • Front or rear seat adjustment selection switch (S55/2s10)
  • Seat ventilation switch (S55/2s11)
  • Seat heater switch (S55/2s12)

Interior CAN 

The signals are read in by the left/right rear door control unit.

The functions resulting therefrom are described in the corresponding function descriptions (see block diagram or function schematic).

Evaluation of input factors 

The input factors that have been read in are evaluated by the integrated microprocessor and the relevant components are then actuated.

Controlling function sequences 

The rear door control unit control the following function sequences:

• Central locking
• Manually or automatically opening and closing rear window
• Automatically closing rear window with PRE-SAFE
• Automatically opening rear window after airbag actuation
• Excess force limiter for manually and automatically closing rear window
• Convenience feature for rear power window
• Switch and control illumination (c. 58d) for rear power window switch

Actuation of components 

Components are actuated with the following lines:

• Direct line 
• Interior CAN 

Direct line 

The following components are actuated via direct line:

• by the left rear door control unit:
  • Left rear door lock unit (A85/3)
  • Left rear door CL motor (A85/3m1)
  • Left rear power locking motor (A85/3m3)

    (with code (883) Power closing for doors and trunk lid)

  • Left rear door additional lock motor (A85/3m4)

    (with code (833) Great Britain version)

  • Left rear child safety motor (A85/3m5)

    (without code (833) Great Britain version and without code (494) USA version)

  • Left rear ashtray illumination (E9/8)
  • Left rear door entrance/exit lamp (E17/5)
  • Left rear door inside handle illumination (E17/13)
  • Left rear door warning lamp (E17/20)
  • Left rear door trim strip illumination (E17/45)
  • Left rear power window motor
  • Left rear side roller sun blind motor

    (with code (297) Roller sun blinds in rear doors)

• by right rear door control unit:
  • Right rear door lock unit (A85/4)
    • Right rear CL motor (A85/4m1)
    • Right rear power closing motor (A85/4m3)

      (with code (883) Power closing for doors and trunk lid)

    • Right rear door additional lock motor (A85/4m4)

      (with code (833) Great Britain version)

    • Right child safety motor (A85/4m5)

      (without code (833) Great Britain version and without code (494) USA version)

    • Right rear ashtray illumination (E9/9)
  • Right rear door entrance/exit lamp (E17/6)
  • Right rear door inside handle illumination (E17/14)
  • Right rear door warning lamp (E17/22)
  • Right rear door trim strip illumination (E17/46)
  • Right rear power window motor
  • Right rear side roller sun blind motor

    (with code (297) Roller sun blinds in rear doors)

Interior CAN 

The signals are transmitted by the left/right rear door control unit. The functions resulting therefrom are described in the corresponding function descriptions (see block diagram or function schematic).

Variants 

• Power closing

  (with code (883) Power closing for doors and trunk lid)

• Roller sun blinds in rear doors

  (with code (297) Roller sun blinds in rear doors)

• Roller sun blinds in rear doors and power closing

  (with code (297) Roller sun blinds in rear doors and with code (883) Power closing for doors and trunk lid)

• Roller sun blinds in rear door and power closing with additional door lock (with code (297) Roller sun blinds in rear doors and with code (883) Power closing for doors and trunk lid and with code (833) Great Britain version)

Thermal protection for rear power window motors

The rear door control units calculate the actuation duration, operating voltage, RPM of rear power window motor as well as outside and inside temperature at the rear power window motor bearings on to protect the rear power window motor.

After a certain threshold temperature is reached, the corresponding rear power window motor can only be actuated until the request is no longer present or the end position is reached.

During automatic raising the direction is reversed when the overload protection force limitation is actuated.

It is possible to reactuate the left/right rear power window motor after a cooling phase calculated by the left/right rear door control unit.

	Wiring diagram for left rear door control unit (DCU)		PE72.29-P-2103-99SAA
	Wiring diagram for right rear door control unit (DCU)		PE72.29-P-2104-99SAA