Hi,
Mercedes C238 E400 2017
my car above has stardust tail lights which fade in and out at night when the car is opened and closed. Looks cool.

Issue - rear right stopped working and part no. Is A2389061101.

I purchased an A2389062101 which fits but it doesnt fade. Just comes on and off

Question - can it be programmed to fade

Thanks in advance
dave
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It's possible it is an issue with your rear SAM. Or some level of reprograming may be needed.

 

There is certainly some programming required because if you haven't notice but for cars without the the full Intelligent Light system (ILS) and which they have only the static front lights in LEDs, the rear actually doesn't do that fading dance despite still being fully LEDs at the back (standard).
Out of curiosity though, how come the previous ones failed, was it a defect? I am surprised because they are relatively good quality LEDs used (unlike the exterior door handle LEDs)

 

My original light developed water ingress and no matter what i did the light never cleared up. I tried drying it out with hot air etc but when returned to the car it fogged over so i decided to replace it but the one i bought was from a 2018 model part A2389062101. Stupidly i thought if it fits it fades but it didnt. Hope STAR can program it to fade as i do have ILS.

 

I see. Other than the fog, is there any issue with the actual function of the light? If you notice your headlights it might too fog at times (MB claims it is normal as the lights aren't completely sealed).

 

The tail light never completely dried out for some reason or another and when i removed it to investigate the issue i never really got to the bottom of how the water actually got in there as i could only see two ways that this could have happened.

Water entering throught the electrical multipin socket or via the rubber capped vent hole.

I sealed the socket and then fitted a rubber tube to the vent hole, applied a slight positive pressure into the fitting by gently blowing down the tube, immersed it water to hopefully see bubbles (reminded me of my bike tyre fixing days) but none appeared ?? The tail light works perfectly btw.

Yes the ILS headlamps do fog up, first time i have seen this on a car this high spec. Design fault in my honest opinion.

All in all the ILS is fantastic on this car. Best lighting system i have had on the 30+ cars that ive owned. Might be a better system out there and interested to hear if there is.

A service on thursday so will hopefully get my reacement tail light programmed to ILS spec.

Regards

 

Hmmm I see, thanks for sharing the details on the previous light and your opinion on the ILS, I agree. Either way, it is the first time I heard about that issue on the rear lights on this car but I am sorry to hear about you having to deal with this. Good luck getting the new lights programmed to spec though.

 

No problem at all, good forum. Sounds like this might not be as easy as i think. Hope to have the new light fading on thursday via STAR but worst case scenario i will dry out and seal the old one. It still works ok, just looks sweaty
Will update post soon....

 

The rear tail lights on my E53 Coupe have the same issue, water gets in and never clears. It's mostly the right side. The right taillight has been replaced twice but continues to develop condensation. I have an appointment in a couple of weeks.

 

Looks like a manufacturing or design issue with these lights if thats the third unit now. Interested to hear the result of your appointment with MB. My replacement unit, albeit from a 2018 model is working well. Last step is to hopefully get the ILS function activated tomorrow.

 

Interesting, second time I heard of this (right after OP's first one), other than them replacing the taillights they didn't state what other causes? Good luck with the appointment. Keep us updated please.

 

I’m currently on my 3rd set of tail lights. 1 driver side and 2 passenger side were replaced due to water getting into the units. If you look closely there is a seam where the white reverse lens and red taillight lens are joined. That is what’s failing and allowing water into the housing.

You would expect better from Mercedes but I must give it to them the design of the lights are sick .. never would have imagined our taillights are 2 pieces.

 

Water in the taillights sounds like my neighbors Prius

 

The dealer replaced the right side taillight, for the third time. They don’t know if the part has been redesigned to eliminate the problem. I’ll know soon enough.

 

I had an issue with my rear lights they would not do the fade sequence.. so I took it to the dealer to get it fix. I told them about the issue and they didn't know what I was talking about I had to show them an example with one of their vehicles.. they took it in for a day and it was fix

 

same problem with my 2020 e300 coupe, dealer says that new set of tail lights will take about 2 months to get here from germany!, really mercedes?, thats the “premium” I paid??

 

Hello Dave! This is a response sometime after your original post, however I had the same issue on my car with the effect not working (light coming on solid instead of like a curtain).

I initially thought there was an issue with the inner light assembly, but I plugged it in on the other side and the curtain effect worked.

So, I proceeded to get my multimeter out and test continuity across the wires to the light. There are two green wires (green with orange stripe, and green with blue stripe) that were broken. The break was in the wire harness at the bend in the hose between the boot lid (“trunk”, in American English). With age, it appears to have collapsed so when you close the boot it pinches on the wires and has broken them.

I rewired the entire harness with same gauge wire (but much thicker insulator) as when I pulled it apart more of the wires broke at the bend. I also had an error code in Xentry for some time about the partition switch having an open circuit or shorted to ground so this explained it all. I used old-school solder joints with heat shrink on each wire and verified all the connections were correct with a multimeter before reinstalling.

In the meantime I’m torn on whether to order and replace the harness to restore to factory, or to keep my repaired one and route it within the trunk instead of the factory hose to avoid it breaking again in X year’s time. Another option is modifying the hose with a thicker middle piece at the bend to accomodate my repair (and reduce chance of that breaking).

Despite above, I’ve reinstalled the empty hose to ensure the boot and boot lid remain water tight.

Hope this is helpful for you and others to fix this issue.

PS: Another important consideration is the harness on the other side, as it would be likely to start failing at the same time if there is a pinch point forming. That harness includes the latch, camera, and light (if the wires to the latch break you’d be locked out of the trunk, unless you have Xentry and can actuate the rear seats or you start the roof open routine to raise the rear window and rear top panel).

 

Good for you on the DIY fix!