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

MODEL 221.0 /1 up to Model Year 8

Fig 1: Locating Rear Door Control Modules

Courtesy of MERCEDES-BENZ USA

Location

The door control units are located in the corresponding door paneling

General

The left rear door control unit and right rear door control unit are connected with the passenger compartment CAN bus for exchanging data.

Task

The left rear door control unit and right rear door control unit read in the following sensors and switches, if necessary, check their indicator light and illumination and switch the following loads via semi-conductor switches.

Controlling and switching loads via semi-conductor switches

Left rear power window motor (M10/5)
Right rear power window motor (M10/6)
Left rear side roller sun blind motor (M24/5) (with code (297) Roller sun blinds in rear doors)
Right rear side roller sun blind motor (M24/6) (with code (297) Roller sun blinds in rear doors)
Left rear CL motor (A85/3m1)
Right rear CL motor (A85/4m1)
Left rear power closing motor (A85/3m3)
Right rear power closing motor (A85/4m3)
Left rear door additional lock motor (A85/3m4) (only in Great Britain)
Right rear door additional lock motor (A85/4m4) (only in Great Britain)
Left rear child safety lock motor (A85/3m5) (not in Great Britain and USA)
Right rear child safety lock motor (A85/4m5) (not in Great Britain and USA)
Left rear ashtray illumination (E9/8)
Right rear ashtray illumination (E9/9)
left rear door entrance and exit lamp (E17/5)
right rear door entrance and exit lamp (E17/6)
left rear door inside handle illumination (E17/13)
right rear door inside handle illumination (E17/14)
Rear left door warning lamp (E17/20)
Rear right door warning lamp (E17/22)
Left rear door trim strip illumination (E17/45)
Right rear door trim strip illumination (E17/46)
Inhibiting rear power window motors with rear side window child safety lock (S20/1s5) pressed in driver-side outside mirror and trunk lid power window switch group (S20/1)

Reading in following sensors

Hall sensors of left rear power window motor
Hall sensors of right rear power window motor
Hall sensors for left rear side roller sun blind motor
Hall sensors for right rear side roller sun blind motor
Left rear rotary tumbler switch (A85/3s1)
Right rear rotary tumbler switch (A85/4s1)
Left rear drive lock pawl switch (A85/3s2)
Right rear drive lock pawl switch (A85/4s2)
Left rear safety limit switch (A85/3s3)
Right rear safety limit switch (A85/4s3)

Reading in the following switches:

Left rear door power window/roller blind switch group (S21/21) with code (297) Roller sun blind in rears doors; with code (540) Electric rear window roller sun blind; with code (413) Panoramic glass roof with top sliding roof; with code (414) Power glass tilting/sliding roof
Right rear door power window/roller blind switch group (S21/22) with code (297) Roller sun blinds in rear doors; with code (540) Electric rear window roller sun blind; with code (413) Panoramic glass roof with top sliding roof; with code (414) Power glass tilting/sliding roof
Left rear seat operation switch group (S55/1)
- 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)
- Heated seat switch (S55/1s12)
Right rear seat operation switch group (S55/2)
- 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)
- Heated seat switch (S55/2s12)

Signal inputs and outputs

Circuit 30
Circuit 58d

Switch functions via rear door LIN

The left rear door power window/roller blind switch group as well as the left rear seat operation switch group are connected with the left rear door control unit via rear door LIN.

The right rear door power window/roller blind switch group as well as the right rear seat operation switch group are connected with the right rear door control unit via rear door LIN.

Thermal protection for rear power window motors

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

When a temperature of T = 85 °C is reached, the corresponding power window motor is actuated only as long as the request is present or the end position is reached. It is possible to reactuate the corresponding power window motor after a cooling phase calculated by the corresponding rear door control unit.