mac911

Have these failures occurred on xenon cars or non xenon cars?

I ask because xenon cars have different rear light assemblies.

Thanks!

Knightmare69

What difference? You mean the led tails? I thought that was just between the years, afaik, there were 3 types of lights for the rears through revisions. The halogen ones that have these issues, the ones with led turn signals and the facelifted led tails.

mac911

Yes, the lighting package cars pre-facelift in US have the LED turn signals, so it is a different assembly overall. I was wondering if those have also failed?

Knightmare69

I can't say for sure but considering they were still using halogen bulbs for everything except for the turn signals its possible that they also can develop this problem, as most of the heat is generated by the parking/brake lights.

4g63pilot

I have the lighting package with the led turn signals. I just noticed my driver side is dimmer last week. Tuesday the car went to the dealer for E service and they said no recall on atleast my car anyway.

mac911

Did you still have them fix it or waiting on a recall?


UPDATE - My car was built Fall 2007 in Germany, so it is over 5 years old, and I have 42,000 miles.
I just unplugged the connectors on each side as shown in the images, and mine look absolutely pristine, new. No signs of any problem. Maybe I don't drive enough at night?

Hope this works out in the end for everyone. I hope disturbing mine won't trigger anything. ha-ha.

justthinking

I had the same issue fixed at a nearby dealer last weekend...
Noticed my right tail light been dim and when I open the check, found bulbs are good with faint but flickr lights..
The holder has some slight brown burn mark on it and the wire connector has melted slightly too...
Dealer replace both the holder and the wire but did not notice if they add a ground or not..

RavenMDX

Can this be fixed as a DIY or do I have to go to the dealer?

justthinking

Someone posted this DIY fix at a Taiwan forum, basically to add a grounding wire to prevent the connector from over-load and melting over time

justthinking

The other way to do this fix is to simply add the grounding and screw it onto the screw post with the red circle, no drilling involved this way

RavenMDX

So essentially splice the brown wire and screw it to the post. Does this actually fix the dimmed passenger lights or just to prevent a complete meltdown?

thanks

Boris0126

This same situation happen to my left rear tail light and I brought it in on 12/27/11 when I saw it that it had melted and this is what they said. "Overheated terminals ground side inspect, replace left and right tail lamp connectors and ground wires, replaced bulb holder assy, clear stored codes"---FP-number: (Qty-1: 204-820-02-77, Lamp Support) (Qty-1: 204-820-01-77, Lamp Support) (Qty-2: 211-545-03-28, Plug) (Qty-2: 000-540-38-05, Cable Harnes) (Qty-2: 002-546-13-41 Cable Connec) I just went outside to check the plugs and so far everything is perfectly fine and I drive with the lights on so let's hope it all stays the same way.

tomduffy14

Hi All - I had the same problem on my 2008 C300. The brown wire insulation was burned away and the black connector plastic was melted next to the brown wire, but the other wires in the connector were ok. Here's a fix that only took about 45 minutes. I didn't mess with the brown wire or black connector at all. There is a thin metal ground plate on the inside of the plastic bulb cluster (the same side that the bulbs are mounted on). I just drilled a hole through the metal ground plate on the bulb cluster, attached a 16 gauge wire to the metal ground plate with a screw and lock washer, ran the wire through a hole in the cluster plate to the trunk compartment, then attached the other end of the wire to a grounded metal bracket. I made the wire from a piece of 16 gauge stranded wire I had laying around, and attached blade terminals to each end of the wire with a crimping tool.

brooktre

My 2008 C204 had the check bulb warning for tail lights. The left rear had a dim bulb, but none of the bulbs were burned out. My connectors looked pretty good - no sign of melting. I traced it down to an internal short in the tail light assembly and then to a "solder ball" that had wedged between to metal strips in the assembly. I removed the solder ball and the problem was fixed. The solder ball appeared to be something that remained when the assembly was made and it apparently became dislodged and ended up causing the short.

VectorBob

Had the exact same problem with my '09. I don't know how long the lights had been dimmer than the other side. Quickly got into the dealership before my CPO warranty expired.
Just like the others the ground connector had burnt/ melted.
They replaced all under warranty but did not do anything about fixing the grounding. Hopefully it won't happen again before I unload the car.

No recall at this point, which I find strange because one would think it's a fire hazard.

BenzManNy

The National Transportation Safety Hazard has over 21 complaints about the same issue. MBUSA is taking their time to resolve but they are working cases as they come. Only issue is that you will have to pay for the "check up" and once done, MBUSA will address the issue. I have an appointment on 12/12 to have mine checked. Only problem is that they charge $125 to evaluate the issue. Hope this helps.

JohnnyC300

I have a 2009 c300 with Premium 2 which includes LED tail lights.

I'm getting the check tail and break light error but the bulbs are not out. Is it possible that I have the faulty wiring harness issue? How difficult is it to check and could checking short it out?


Benzman, any update? How much did it cost I am getting B service done this week and may want to have this added on.

VectorBob

The only thing you could do is unplug the wiring harness from the bulb carrier and visually inspect both looking for the burned or melted ground.

When I had my issue, I had no error message on instrument console.

angelas111

I'm gonna try to add a ground wire today and hopefully that will help brighten the right tail light. I'll post my results.

JWH321

OK, I began getting the message on mine. I have a 2008 with the premium package and LED turn-signals.


I pulled the wiring plugs on both sides to see if they are burnt -- neither is, but the error message is still popping up. All of the lights work, including the rear fog light.


Any ideas? I have just been hitting OK to turn off the message, but I'm a bit worried that I should be doing something to fix this before something fails.

brooktre

I was able to fix mine without doing any modifications - see post #39.

JWH321

Did you pull the taillight housing completely off the car to inspect it?

brooktre

You just unplug the wiring connector and then remove the assembly by depressing plastic tabs (I think there were 2 of them). Using a volt / ohm meter I figured out which wire controlled what and was able to determine that there was a short within the assembly. Close visual inspection revealed a "ball" of solder that was wedged between 2 of the metal strips that are used to transfer energy through the assembly. When you remove it should be easy to see what I mean.

JWH321

Thanks so much. I have it apart and sitting on the bench in front of me, and now I do see the strips. I've never seen a light assembly made that way -- interesting. I bought it all new bulbs while I was at it, the two bottom ones on either side looked like they had a "burned" coating on them on the inside, even though they still functioned.


And you are exactly right, there are two small clips at the top and bottom of the flat plate that holds the lights and the LED connectors for the turn signals. VERY easy to remove.


I'm a bit perplexed. I see the ground wire is a fairly small gauge wire that handles the return for all of the lights, and the metal grounding plate is very large in comparison to the wire. I see no signs of burning or overheating in either the connectors or the light plate itself. Its been fine for nearly 80K miles now, but, given the issues others have had, I'm wondering if I should make it an additional ground connection. Your thoughts?

brooktre

When my message popped up, it said right rear bulb. However, it was the left rear assembly that had the problem (a search said that other owners also got the message for the side that was OK). I tried replacing all bulbs on both sides, but this did not work. With both assemblies out and in the trunk hooked up, I had one or two bulbs that were dim on the left side. After unplugging the assembly and removing all bulbs, I check the resistance between the ground side of the assembly and the other circuits. Eventually I found the one that had the problem and then located the stray solder ball.

I would think that adding an additional ground would not be necessary if everything is working, but I'm not an electrical expert.