06-07

W211 rear lights - repair?
 

Hello Merc Friends -

Am looking at a 2005 W211 - an E320 4-Matic. Having a feeling there will be many things to ask about, but to start:

One of the rear lights needs repair/replacement. I see the individual bulbs cannot be replaced; that there is a full assembly/board which must be replaced.

I see these are already becoming difficult to find... Meanwhile...

Has anyone tried to simply repair these boards? Like by simply soldering in a replacement bulb or two? Any insights? I assume these are all 12V pretty standard bulbs?

Are you sure the bulb is bad? You should hook up SDS or a MB capable bidirectional scanner to confirm the problem isn’t (also) in the SAM. With these cars, the issue is rarely just a bulb.

[Edit] I just learned that if the corresponding other side light works then it’s probably not the SAM. Check for burned traces on the board which you might be able to repair. There are aftermarket bulb carriers for the 211.

Sixto
05 E320 wagon 212K miles

No, not sure at all. Still in 'evaluation mode', so don't have full access to the vehicle yet. Such a thing would be unlikely to stop my purchase, though, so am simply looking for all the insights I can gather...

What's an SDS? SAM looks like 'System'(?) (something) 'Manager'(?)

Do feel free to suggest the right diagnostic tool/software you guys use for this car...

Having lived a life in abbreviations and acronyms, I try to avoid them as much as possible!

Continuing Ed now says there is one wire from the SAM to each bulb.

SAM is signal acquisition module. These cars aren’t wired point-to-point, rather through networked modules. IIRC the 211 has 3 major SAMs. You or the ambient light sensor decide to turn on the tail lights and the relevant SAMs convene to decide whether to execute.

SDS is star diagnostic system, MB’s service device. Bootleg software and multiplexers and a laptop to make it work is about $800 turnkey from China. There’s a steep learning curve but lots of US support for the asking.

The Autel AP200 is a highly rated by MB forums for working on these cars. There’s quite a learning curve but it’s ‘only’ $70 and works with Android or iOS. You can pay a lot more for not as comprehensive a scanner.

Agreed, a malfunctioning tail light isn’t reason to dismiss a prospect but make sure it’s not the warning sign of an electrical nightmare.

Sixto
05 E320 wagon 212K miles