I got a 2008 C300 Sport from my neighbor recently. I've fixed a few issues but I am stuck with the remaining ones. I've read that the Front SAM could be the culprit for everything but being that I've fixed several other issues with cleaning the CANBUS, I figured maybe I should verify one here. Also, the PO changed the Front SAM already.

All codes have been pulled with an Innova 5610 v3

Current Codes...
U141E00 - An Implausible Signal From Switch "Exterior Illumination" Was Received.
U115000 - Communication With Switch "Exterior Illumination" Has A Malfunction.
U115100 - Communication With Switch Group "Warning System" Has A Malfunction.
A22755 - There Is An Internal Fault In Control Unit "Tilting/Sliding Sunroof". The Component Is Not Configured.
U012787 - Communication With The Tire Pressure Monitor Has A Malfunction. The Message Is Missing.

Dash warnings...
Front Right SRS Malfuntion Service Required
Tire Pressure Monitor Inoperative

Other issues...
ESP Button/Lights not working.
Hazard button not working.
Seat heaters not working (no lights on buttons)
Read sunshade not working (no clicking or sounds from motor)
Interior light buttons not working
Rear interior light button not working
Front map light buttons not working
Door open/close front light working but the "off" button to NOT turn on when door is opened is not working
Sunroof goes back just fine and tilts up just fine, but starts and stops when closing from open and closing from tilt.
I'm not even sure what it is supossed to do, but the knob on the center console will center click, move up/down & left/right but I have no idea what the spinning click dial is even for to know if it works or not.


What I have done...
Found and cleaned the CANBUS in the passenger floorboard wire tunnel. (had water marks, cleaned with CRC Electronics Cleaner)
Found and cleaned the CANBUS in the driver floorboard wire tunnel. (had water marks, cleaned with CRC Electronics Cleaner)
Pulled and cleaned Rear SAM (no water marks).
Pulled and cleaned Front SAM (no water marks).
Pulled and cleaned the overhead control panel (no water marks).
Checked all fuses in Front SAM and Rear SAM. All good. (found a diagram online for what fuses were what but on the Rear SAM it was saying there are fuses where there are no wires for the fuses).

What PO said he did...
Replaced Front SAM with same model number (did not reprogram)
Purchased Rear SAM with different model number (installed but didnt work, said I need to get it programmed for the car, original SAM currently installed)

Any suggestions and where to look? More info on certain problems?

 

I'm going to say you try this.
Since it seems your neighbor has been all over this car you don't realty know what they have done.
If you suspect the rear Sam and can find one on eBay from the exact model and relatives close year it might be plug and play. Same with the others but they have additional security to get around so will need programming to probably at a minimum match Vin number to yours. Butt could need to change many varient codes to match what's installed in your vehicle.

Some can do it remotely or you can invest inn the software and tools and do it if your able to learn.

 

From what I’ve read the MB software/tool is the only one that can program the SAMs. Is there another option besides the MB one? It’s a bit too pricey for only being able to use it for MB vehicles. If there is an option that can be used on multiple makes then it may be worth it.

 

I'm sure there are high end tablet scanners that do multiple vehicles. Butt I would bet for full programming support you will have to pay a monthly or yearly support cost. But I dunno I. Have the Mercedes software.

 

I replaced the rear Sam with one from another 08 C300 RWD and a few things are working again. What is still not working is listed below…

Drivers Side SAM
U141E00 - An Implausible Signal From Switch “Exterior Illumination” Was Received.
U115000 - Communication With Switch “Exterior Illumination” Has A Malfunction.
U115100 - Communication With Switch Group “Warning System” Has A Malfunction.

OCP - Overhead Control Panel
A22755 - There Is An Internal Fault In Control Unit “Tilting/Sliding Sunroof”. The Component Is Not Configured.

As for button functions, the below still don’t work.
ESP Off button
Hazards do nothing but blinkers work.
”Pass Air Bag” off light not showing when no passenger is in the car.
Rear window shade not moving or making any noise at all.
Neither Left nor Right seat warmer buttons lighting up.
Neither drivers nor passengers map light (behind fold down shades work.
Rear light doesn’t work
pushing the button to control if lights come on when door is open isn’t working.
And sunroof still not closing smoothly from open or from tilt. Open and tilt still work fine.

 

If the front sam was replaced with a used one from a car with a different style exterior light switch then it wont work. I was having issues with my exterior light switch and when looking for a used switch I noticed my specific one wasnt that common. Mine you pull out once for front fog lights then pull out again to active the rear fog light. Others i've seen have separate buttons for the fog lights. Also some have Auto and some dont.

I would pull the specific wiring diagrams for your car and start testing things.

Example the map lights behind the fold down shades. Im assuming thats the sun visor? Pull the bulb and test the connector, then trace the wires back to see where the break in power is.

 

Can try reseting the sunroof.

 

I'm having a similar issue with my 2022 S650 where the iDrive software freezes every now and then. I've noticed it mostly happens when I plug in my phone via USB, so I've started using the wireless connectivity, and the problem seems to have gone away. Worth a shot, maybe it'll work for you too.

 

I've tried that multiple times and it still does the same thing. I’ve read that the overhead control panel could be bad. I’ve taken it out but didn’t see anything that would explain the symptoms.