[bpeter]

Car model: C300
Model year: 2008
W204

My driver seat backrest control using the seat switch stopped working in one direction only. I can move the seat forward and back, adjust seat height up and down, however, I can only move the backrest so that it leans further back (I cannot make it lean forward using the switch).

Can someone post the wiring diagram for a driver side switch for a C300, year 2008 (W204)? (with no seat memory option)

Also, does the switch that is on the side of the passenger seat directly control the motors, or is there another control module that the switch connects to, and that control module then connects to the motor? I do not have the seat memory option in my car, so it would be great if someone could confirm this question. Obviously the motor works, since the reverse movement just means a reverse polarity on the same motor.
I will check the fuses next, but I suspect they will be fine, since all of the functions (except for one) work. The fuse numbers for the front seat adjustment are: 2, 3, 44, 45, 116, 126

Also, can someone confirm if I have to remove the seat to replace the switch (in other words, is it accessed from below the seat) or does the plastic molding on the side of the seat need to be removed to uninstall and replace the switch.

 

[bpeter]

I checked the fuses today and they are fine. Also, based on what I could see below the seat (without removing it), the seat control switch directly controls the individual motors (my car does not have the memory feature for the seat position, so there is no separate seat control module).

I ordered a replacement switch and will report back once I complete the repair.
The driver side front seat control switch original MB part number is A 2048701658 (in case this helps anyone).

If someone has the wiring diagram, I would still be interested in seeing it.

 

[mattml430]

You might want to pull the switch apart and check it, might be just a dirty contact.


Sent from my iPhone using Tapatalk

 

[bpeter]

I replaced the seat control switch and that fixed the problem.
I had to remove the seat as a part of the process. I recorded some of the steps and will post the video in case that helps anyone with the same switch issue.

 

[bpeter]

Below is the link to the video on how to replace the seat control switch. The job took less than 1 hour to complete.