SAM problems?
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SAM problems?
Hello, I own a 2004 MB c-240 that was working and running fine until I had the alternator and battery replaced. Shortly afterwards the car’s electronics started malfunctioning. The a/c,blinkers and speedometer were first next,the windows all working intermittently. As time passes more things are starting to malfunction. I put a code reader on it and got a lot of “no communication to can”. At least I believe that is what it said. As is,I can’t get it inspected so it’s been parked. The mechanics are outrageous @ $200 hr. So, I’m looking for help so I can try DIY
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Joined: Jul 2017
Posts: 1,004
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From: Richmond, VA Metro Area
2005 C230 Sport Sedan-6 Speed Manual
The front SAM is a component that seems to fail fairly frequently. A common belief expressed on the forums is that the power surge from reconnecting the battery can cause a marginal SAM to fail. So, it is possible that the alternator replacement led to a front SAM failure. Some of your symptoms, such as the problem with the blinkers, are similar to the ones I cured by replacing my front SAM.
I'm reluctant to recommend that you "throw parts at a problem" especially because a new SAM will probably cost more than $250 from an on-line seller. However, it may be worth a shot. It sounds like the cost of a front SAM would be about the same as an hour-and-a-half of labor in your area. I suggest that you search this forum using the term "Front SAM." If you read several posts that confirm your symptoms are caused by a failed SAM, I think it would be sensible to replace the SAM.
Replacing the SAM is something that a person with some basic mechanical skills can do. There are several YouTube videos showing how to do it. Here's one:
The most tedious part of the process is accessing one of the torx fasteners that secures the SAM to the vehicle. There are many connectors that attach to the SAM. If you work systematically and take pictures as you remove the connectors, you should be able to install the new one with a minimum of fuss.
I ran into one issue when I replaced mine. I have a car with a manual transmission, and I needed to make a change to the settings in the SAM due to an issue with the reverse lights. You can read about my experience here. This required the use of the Mercedes STAR system. If you have a car with an automatic transmission, you should not have this issue.
Good luck.
I'm reluctant to recommend that you "throw parts at a problem" especially because a new SAM will probably cost more than $250 from an on-line seller. However, it may be worth a shot. It sounds like the cost of a front SAM would be about the same as an hour-and-a-half of labor in your area. I suggest that you search this forum using the term "Front SAM." If you read several posts that confirm your symptoms are caused by a failed SAM, I think it would be sensible to replace the SAM.
Replacing the SAM is something that a person with some basic mechanical skills can do. There are several YouTube videos showing how to do it. Here's one:
The most tedious part of the process is accessing one of the torx fasteners that secures the SAM to the vehicle. There are many connectors that attach to the SAM. If you work systematically and take pictures as you remove the connectors, you should be able to install the new one with a minimum of fuss.
I ran into one issue when I replaced mine. I have a car with a manual transmission, and I needed to make a change to the settings in the SAM due to an issue with the reverse lights. You can read about my experience here. This required the use of the Mercedes STAR system. If you have a car with an automatic transmission, you should not have this issue.
Good luck.
Last edited by KevinH2000; Oct 13, 2024 at 09:52 AM.
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Joined: Apr 2009
Posts: 317
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w203cl
Window regulators have nothing to do with the SAMs, I would guess a loose ground connection. Start engine and measure the voltage from the engine to the ground cable at the battery, should be below 40 mV.
