Lisa Marie

hello,

I had my battery and CAN blocks replaced due to water damage from clogged sunroof drains. After some heavy rains the other day and only 6 days out of the repair shop I have the same problems as before. Auto lamp function inoperative error msg, wipers not working, both turn signals not working, error msg to check brake and tail lamps and when I shut the car off tail lights/brake lights stay on. I brought it back to the shop and they said it is a faulty rear SAM.

Has anyone had a similar problem? I am concerned that replacing the SAM is not going to fix the problem. I spent 1700 on the repairs last week and to replace the rear SAM will be 1100. The shop said there were no problems with SAM when car left there last week. Dealership initially diagnosed the water damage and they reported no problems with SAM.

Any help would be immensely appreciated. Thanks so much!

Irfie

Disconnect the SAM and connect it again, it might be a lose connection.

Additionally, I would recommend to check all your fuses related to that, a faulty fuse can also trigger this issue.

Can you provide which model do you have? It would be helpful for me to advise you further.

Lisa Marie

2008 C300 4matic. I spoke to the shop this morning and he said it is def a faulty SAM. I still don't understand why it worked with the corroded CAN blocks but fails after they are cleaned and replaced.

Lisa Marie

Now after the new SAM went in my battery sensor isn't working correctly. I bought this car in 2011 CPO and since then put about 50K miles on it. I've kept up with the maintenance and after this electrical issue is resolved I have another 2500 in repairs. One being new engine and trans mounts. I thought these cars were built to last and I'm disappointed in the problems I'm having at 85K miles.

I'm so confused on what to do with this car. Should I make the repairs and hope to get another year or two before needing more costly repairs or trade it in? And if I trade it in is it worth replacing the engine mounts first?

Any thoughts? Thanks so much.

LandSeaAir

same thing happened to my car, replaced the SAM and it was like new.

Not sure what a battery sensor is but when you replace the SAM, you either have to get one from a wrecked C that has the EXACT options/specs as your car OR if you got it new from the dealer, then they have to program it to the car. Otherwise, if you put a SAM in from a different spec'd C Class, the features on your car that weren't on C-Class which sourced the parts won't work.

I'd say keep the car. 204s are simple, easy to fix cars and mine has never had any unexplained electronic gremlins nor have I heard of any others having this... find a new shop. In terms of long term reliability + quality for the $... cars don't get much better than this.

Lisa Marie

I found a very experienced shop from this site actually. He ordered me a new SAM and programmed it. I'm waiting for him to call me today with an update. He didn't give me the option of getting a used one.

LandSeaAir

Well sounds like he messed up the programming if there is stuff not working, just a guess.

LandSeaAir

For future SAM issues:

I paid $175 for my SAM a few years ago and installed it. The most difficult part was unplugging the wires underneath the SAM, but otherwise it was an even swap.


I searched for a fuse box (engine) for a 2008-2010 C-Class:

http://www.car-part.com/cgi-bin/search.cgi

This is the kind of result you get... (copying the link doesn't work).


Theres probably 200 more results... call each place, ask for the vin number, plug the vin number into here:

https://www.vindecoderz.com/EN/Mercedes-Benz

And make sure the car has the exact same options as yours (e.g. heated seats, comand, rear sunshade, etc.) there are so many SAMs available that you want to make sure it comes from a car with the EXACT specification as yours.

I fixed the car pretty easily for $175 and was real impressed with how plug and play, and perfect the car was after the installation.