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Access power seat control module

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Old Nov 26, 2021 | 01:50 PM
  #1  
Lou S's Avatar
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C300 W205
Access power seat control module

Folks- need some advice. Has anyone replaced the power seat control module(s) on a c300 w205? I have the infamous parasitic battery drain coming from my front right module and am wondering what the best way is to access it is (looking to replace the module vs re-splice the wires and just run switched power).

I could unbolt the seat rails but I think the module is bolted to the seat frame vs floor. Do I pull the seat cushion instead? Any advice appreciated, pictures even more so!

Thanks,
Lou
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Old Nov 27, 2021 | 08:55 PM
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W212 MY'14 M276-3.5NA @75kMi
flaky seat module...

Gone are the days of simplicity! These days seat modules are computer controlled by a CAN network. They host functions like SRS AirBags, belt sensors, heaters, motors ...
Provided you did not wait too long, your unit maybe easy to fix with a few bad solders connections.

To get a hold of your seat unit, first unplug your batteries, unplug couple connectors from under the seat and pull the unit.
If you are unfamiliar go ahead, pull the whole seat to gain better access. (Power disconnect is to safely put SRS circuits to rest!)


solder side ... all fixed.

zoom on bad solders

overall view of driver seat ctl

Have a long look at your unit to hopefully locate your trouble junctions...
..

Last edited by CaliBenzDriver; Nov 27, 2021 at 09:11 PM.
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Old Nov 28, 2021 | 12:28 PM
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C300 W205
But how do I pull the module?

thanks @CaliBenzDriver . Appreciate the detail re the solder connections, but my first step is to actually pull the module. Was wondering if the best way to access it is by unbolting the seat rails (prob not), removing the seat cushion, or something else.


Originally Posted by CaliBenzDriver
Gone are the days of simplicity! These days seat modules are computer controlled by a CAN network. They host functions like SRS AirBags, belt sensors, heaters, motors ...
Provided you did not wait too long, your unit maybe easy to fix with a few bad solders connections.

To get a hold of your seat unit, first unplug your batteries, unplug couple connectors from under the seat and pull the unit.
If you are unfamiliar go ahead, pull the whole seat to gain better access. (Power disconnect is to safely put SRS circuits to rest!)


solder side ... all fixed.

zoom on bad solders

overall view of driver seat ctl

Have a long look at your unit to hopefully locate your trouble junctions...
..
Reply
Old Dec 1, 2021 | 11:27 PM
  #4  
CaliBenzDriver's Avatar
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W212 MY'14 M276-3.5NA @75kMi
releasing module from seat

MB made this module nice and easy to service after failure. If you're comfortable with a wrench, this is child's play practice... designed to be easily repaired

- Remove the 4x bolts for the seat rails (5 minutes)

- then rock the seat back while watching the seat harness to prevent any pull....

- unplug the couple connectors to your black-box seat module

- Depress catches to release module from frame
- open black-box by releasing a dozen loops
- post good pics so I can point things out to fix circuit board. Concentrate on edge connectors and relay solders, it's nothing too seriously involved.

Once you're done, the passenger side seat controller will be a game!

Saving $2k before Xmas never been as much fun ... next you want to fix your door modules in 10mn!
​​

Last edited by CaliBenzDriver; Dec 1, 2021 at 11:48 PM.
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