Door control module
Overview
Door control module (in WIS) or Electric Seat Adjuster Switch (in EPC) is ... When looking for part in catalogues, you may need to add 7C45 to end of part number (e.g., A22082106587C45).
The door control module in itself is pretty dumb device. All key presses are sent over CANBUS to SAM. SAM then broadcasts message to all modules and module which understands the message acts appropriately (whether lighting up some bulb, engaging seat heating, moving seat, etc.).
Location
In door panel hold by plastic clips.
Connectors
PICTURE
Using right hand drive DCM in left hand drive vehicle
It has been tested that RHD DCM A2208212179 installed on left side of LHD vehicle originally equipped with A2208214179 will work fine, however, the mirror controlling switch will not work and window controlling switch will be able open only driver's door window. Similarly, RHD DCM A2208211879 installed on left side of LHD vehicle originally equipped with A2208214979 will work fine, however, the window opening switch will open left side driver's door window.
Using left DCM on the right side
The physical location of DCM is programmed into DCM. E.g., if left DCM is connected to right side, the DCM will still move left seat.
Seat ventilation
Seat ventilation functionality does not depend on DCM. Appropriate buttons are not part of DCM and can be bought separately.
Upgrading to DCM supporting memory seats
It seems that seat memory function is determined by DCM itself.
It has been tested that vehicle originally equipped with DCM A2208214179 in drivers doors can be replaced with DCM A2208211579 and memory seats will work out of the box. To mount DCM with memory buttons appropriate door panel with holes for memory buttons must be mounted. Alternatively, if memory functionality is not needed, one can replace front control board connected by wire with control board from A2208214179.
List of door control modules
Facelift (from 30/09/2002)
Front Left
| Part No. | Front | Back | Controls board | Board side A | Board side B |
|---|---|---|---|---|---|
| A2208214179 (left hand drive vehicles) | 
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| A2208211579 (left hand drive vehicles) | 
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| A2208214479 (right hand drive vehicles) | 
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| A2208212179 (right hand drive vehicles) | 
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Front Right
| Part No. | Front | Back | Controls board | Board side A | Board side B |
|---|---|---|---|---|---|
| A2208214979 (left hand drive vehicles) | 
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| A2208211679 (left hand drive vehicles) | 
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| A2208215079 (right hand drive vehicles) | |||||
| A2208211879 (right hand drive vehices) | 
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Rear Left
| Part No. | Front | Back | Controls board | Board side A | Board side B |
|---|---|---|---|---|---|
| A2208216279 | 
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| A2208215779 | 
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| A2208212379 | 
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| A2208212779 (right hand drive vehicles) | 
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Rear Right
| Part No. | Front | Back | Controls board | Board side A | Board side B |
|---|---|---|---|---|---|
| A2208216879 | 
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| A2208216379 | 
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| A2208212479 | 
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| A2208212879 (left hand drive vehicles) | 
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Pre-facelift (to 01/09/2002)
Front Left
| Part No. | Front | Back | Controls board | Board side A | Board side B |
|---|
Front Right
| Part No. | Front | Back | Controls board | Board side A | Board side B |
|---|
Rear Left
| Part No. | Front | Back | Controls board | Board side A | Board side B |
|---|---|---|---|---|---|
| A2208211558 (to date 30/06/2001, replaced by A2208214958) | 
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| A2208214958 | 
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| A2208215558 (right hand drive vehicles) | 
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Rear Right
| Part No. | Front | Back | Controls board | Board side A | Board side B |
|---|---|---|---|---|---|
| A2208211658 | 
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| A2208215058 | 
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| A2208215658 (left hand drive vehicles) | 
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Resources
Replacing DCM: https://www.youtube.com/watch?v=ElIIDz-vq4w
Repairing water damage in DCM: https://www.youtube.com/watch?v=6hUF1DjqrWI
Making your own DCM control buttons: http://www.benzworld.org/forums/w220-s-class/1624796-seeking-rh-headrest-adjuster-button.html