Left front door control unit, component description - GF72.29-P-4141LE

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

Location 

The left front door control unit is located on the rear door module behind the door paneling on the left front door.

Task 

The left front door control unit has 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 with the following connections:

• Direct line 
• Front door LIN 
• Interior CAN 

Direct line 

The following sensors are read in via a direct line:

• Driver door infrared sensor (B58)
• Hall sensors of left front power window motor (M10/3)
• Mirror adjustment up/down potentiometer (M21/1r2) (with code (275) Memory package (driver seat, steering column, mirror))
• Mirror adjustment in/out potentiometer (M21/1r3) (with code (275) Memory package (driver seat, steering column, mirror))

The following switches are read in via a direct line:

• Left front rotary tumbler switch (A85s1)
• Left front drive lock pawl switch(A85s2)

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

• Left front safety limit switch (A85s3)

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

The following signals are read in via a direct line:

• Circuit 30
• Tml. 31

Front door LIN 

The following switches are read in via front door LIN:

• Driver power window outside mirror and trunk lid switch group (S20/1)
  • Left front power window switch (S20/1s1)
  • Right front power window switch (S20/1s2)
  • Left rear power window and side window roller sun blind switch (S20/1s3)
  • Right rear power window and side window roller sun blind switch (S20/1s4)
  • Rear side windows child safety lock switch (S20/1s5)
  • Remote trunk lid open/close switch (S20/1s6)

    (with code (881) Remote trunk closing (RTC))

  • Outside mirror fold-in/fold-out switch (S20/1s9)
  • Left/right outside mirror adjustment selection switch (S20/1s10)
  • Outside mirror adjustment rocker switch (S20/1s12)
• Left front seat operation switch group (S22)
  • Head restraint adjustment switch (S22s1)
  • Seat cushion forward/back switch (S22s2)
  • Fore/aft, height and inclination adjustment switch (S22s3)
  • Backrest switch (S22s5)
  • Memory switch (S22s6) (with code (275) Memory package (driver seat, steering column, mirror))
  • Memory switch 1 (S22s7) (with code (275) Memory package (driver seat, steering column, mirror))
  • Memory switch 2 (S22s8) (with code (275) Memory package (driver seat, steering column, mirror))
  • Memory switch 3 (S22s9) (with code (275) Memory package (driver seat, steering column, mirror))
  • Left or right seat adjustment selection switch (S22s10)
  • Seat ventilation switch (S22s11) (with code (401) Front comfort seats incl. seat heater and seat ventilation)
  • Seat heater switch (S22s12) (with code (401) Front comfort seats incl. seat heating and seat ventilation)
• Left interior CL [ZV] switch (S85/5)

Interior CAN 

The signals are read in by the left front door control unit via the interior CAN.

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 left front door control unit controls the following function sequences:

• Outside mirror adjustment
• Blind spot assist indicator

  (with code (234) Blind spot assist)

• Power window actuation
• Driver door interior illumination
• Central locking
• Left additional door lock

  (with code (833) Great Britain version)

Actuation of components 

• Left front door lock unit (A85)
  • Left front CL motor (A85m1)

    Left front power closing motor (A85m3)

  • Left front additional lock motor (A85m4)

    (with code (833) Great Britain version)

• Left outside mirror turn signal lamp (E6/5)
• left front door entrance and exit lamp (E17/3)
• Left front door inside handle illumination (E17/11)
• Front left door warning lamp (E17/19)
• Left front door trim strip (E17/43)

  (with code (876) Interior light package)

• Left front power window motor
• Left electrically adjustable and heated outside mirror (M21/1)
  • Left outside mirror ambient lamp (M21/1e1)
  • Left Blind spot assist warning indicator (M21/1e2)

    (with code (234) Blind spot assist) (left-hand drive vehicle)

  • Left Blind spot assist indicator lamp (M21/1e3)

    (with code (234) Blind spot assist)

  • Automatic mirror dimming (M21/1h1) (with code (249)
  • Automatically dimming inside rearview mirror and outside mirror (driver))
  • Mirror adjustment up/down motor (M21/1m1)
  • Mirror adjustment up/out motor (M21/1m2)
  • Power folding mirror motor (M21/1m3)
  • Mirror heater (M21/1r1)

Variants 

• Blind spot assist (with code (234) Blind spot assist)
• Mirror dimming (with code (249) Inside rearview mirror and outside mirror (driver) automatic dipping)
• Additional door lock (with code (833) Great Britain version)

Thermal protection for left front power window:

The left front door control unit calculates the actuation duration, operating voltage, RPM of the left front power window motor as well as the outside and inside temperature at the bearing points on the left front power window motor to protect the left front power window motor.

After a certain threshold temperature is reached, the left 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 front power window motor after a cooling phase calculated by the left front door control unit.

Wiring diagram for left front door control unit (DCU)

PE72.29-P-2101-99SAA