iFlyE55

I've had my car about a month and a half. About a week ago, the right low beam quit working. At the same time, I noticed that the left low beam would start flickering when off, although worked just fine when on.

A few days later, the left low beam quit working entirely.

All of the other lights work just fine, including the high beams. This would make me think ballasts (at least for the right side), but I'm wondering if there isn't some lighting control module that might not be acting up (if such a thing exists).

Ideas?

cmriv

xentry/DAS/SDS would be the only way to decipher what is really going on. Unless you have a budd with the same xenon control units as you, you could swap them. Otherwise anything else is speculation.

Not sure where those control units get power from, but a known issue on the w211 chasis with lights not working, if bulbs/ballasts/and control units are fine, front driver side sam....

iFlyE55

Thanks for the response.

Dumb newbie questions:

I'm thinking about getting a STAR diagnostic tool. Is that going to be different from xentry/DAS/SDS?

What is the "front driver side sam"?

cmriv

There are a few members on here that have the tool. I would search and find someone who has everything, and everything working properly. They are the same thing....


It is a signal acquisition module or relay module. It powers things up and makes magic happen. It's a electronic component, next to your brake fluid reservoir covered by a black cover that has two slide tabs on it....

cetialpha5

And if we are just speculating, the simple answer could be cheap aftermarket Xenon bulbs assuming you have the bi-xenons. Get a set of real ones from a known source, there's lots of fakes out there especially on eBay and even Amazon. And if that's not that answer, then you've got problems as mentioned above.... You might be able to find a member near you that has a system or ask some indys if they have such a system. Or just take it to the dealer and have them charge you for the diagnostic.

cmriv

+1 on the stealer diag....

iFlyE55

I'm thinking there's something wrong with the headlight module.

I've noticed that if I flip the turn signal stalk back to turn on the high beams, it does that whether the headlight switch is in the on position or not. Does that seem correct? I'm thinking it shouldn't be, but don't know the intended function well enough.

iFlyE55

Getting back on this:

I'm going to try replacing the SAM.

Questions:

1) It looks like other Mercedes with a SAM have a front left, front right, and rear SAM. Given the problem is with the low beams, the assumption is that it's the front left SAM?

2) Where is the SAM located?

Thanks