2010 W221 Rear LED Sidemarker Problem
 

All -

Looking for any insight on a problem with the passenger side taillight on my facelift W221 S400. I returned from a trip to pick up the car at the airport displaying a dash message that the right rear sidemarker was not working. On inspection, the upper LED section of the tail light was completely dark, the lower section was fine, as was the entire left tail light.

I did a fair amount of web searching but came-up empty. The question I have is whether this is more likely a problem with the taillight unit or something more nefarious. It's disappointing given that I've only had the car for a week! I did try unplugging and reconnecting the wires to the taillight, and it did flicker once when I closed a door hard (only time I got it to flicker, and hasn't done it since). at $400, I really don't want to start throwing parts like taillights at the car unless it is very likely the problem. I did speak to a tech I know, but he responded that it wasn't a problem he'd seen before so really had no insight.

Thoughts? Any insight is appreciated!!

-Reed
'11 E350 Wagon
'10 S400 Hybrid
'85 300SD

Check the lamp support for corrosion, if not repairable replacement is part # 2218200677 MSRP $48, $28.08 + shipping http://huskerparts.com/partlocator/i...?siteid=215771 removal: http://workshop-manuals.com/mercedes...ar/page_12967/ & http://workshop-manuals.com/mercedes...tall_taillamp/

Thanks!! Looks like ordering that part is next. Cleaned the contacts, and the upper LED flashed a few times (interestingly - it seemed to flash very rhythmically - maybe 5 or 10 times, once per every second or two. Not flickering, but a distinctive flash. Before I order the socket, does this reek of something else?

Again ,much appreciated!!

-Reed

So I got the bulb/socket support and installed this morning. No dice. Same error message about the right rear side marker, and sure enough that array of LEDs is still dark. So this begs the question of whether I should replace the tail light unit for about $400, which includes the circuit boards inside, or whether I should take it to a qualified shop to diagnose in case it is some bigger issue (SAM, etc.).... BUt in addition to paying for parts for repair I'll be paying labor too...

Ugh.

Any opinions are appreciated!!

-Reed

Left side internals (2218200577) are shown here http://www.ebay.ca/itm/2010-13-MERCE...736eb2&vxp=mtr common for lamp support to corrode causing complete circuitry to fail. Revisit right side connections - LED panels & circuit panel itself. If fine, see if you can pull 10 digit part # from LED panels to search online or, replace tail lamp. Consider shopping used 221820064 or 2218201464 to obtain circuitry, read damage description carefully and confirm circuitry is fine before purchasing i.e.: http://www.ebay.ca/itm/2010-2013-MER...79d562&vxp=mtr

Thanks again! Dumb question: can the left side lamp be plugged-in on the right side just to test whether the full lamp is getting power to it?

@konigstiger: On the lamp support, there are two backup bulbs with gray base (921). What is the 3rd bulb on top, with the black base? Rear fog? EPC does not seem to show that part. Thank you.

Certainly worth trying. ;)

EPC: 12V-16W x4 = left & right backup & turn signal bulbs, shown in link top 19W fog left only.

The white LED (parking light) strip incorporated into my right side headlight is half out. I had a similar issue with the left side and replaced the entire headlight assembly...PRICEY! I'm curious if any one if familiar with a source who can/does repair these assemblies OR can direct me to instructions on a DIY repair?

So to close the loop on this, a new taillight cured the problem.... Admittedly, I bought aftermarket. Perfect match.

Thanks for the help!!

-Reed