Troubleshooting the headlights for the 2020 W205 model.

[MundeDas]

I apologise if this has already been addressed, but I'm struggling to find clarity on this matter.

I own a 2020 C-Class equipped with the sophisticated Multibeam headlights. The original offside headlight was entirely filled with water, causing the daytime running light, indicator, and adaptive main beam assist to cease functioning. Instead of spending £1500 on a new headlight from Mercedes, I found a used headlight in good condition on eBay for £350.

The headlight is functioning properly, yet the original issues mentioned above persist. I am uncertain whether this is merely a coding problem, but I have attempted to replace the module with the original headlight module without success. I would greatly appreciate any ideas or pointers! 😊

[AmericaMonster]

How many miles or months past the warranty is the car?

If there was no accident damage, why didn't you request a goodwill contribution from MB?

Regarding the replacement. Is the part number identical to the original? If that’s not the case, it might not be compatible, or, if you’re fortunate, it could require some coding.

[MundeDas]

Unfortunately, the warranty expired on January 31st, and the issue began just a few weeks ago when the weather took a turn for the worse. 😔

I contacted Mercedes Teesside, but I was informed that there would be a charge of £175 just to look into the issue (though this is at the technician's discretion, and it might be resolved at no cost).

Indeed, the part numbers align perfectly, and it functions as intended. The original issue continues to persist, which makes me believe it simply requires clearing or coding.

[AmericaMonster]

It seems you were hesitant to invest £175 (or perhaps even less) on a diagnostic fee, which, had the headlamp not been damaged, likely would have led to some goodwill shortly after the warranty expired. Now, however, you find yourself £350 in and still no closer to a resolution?

[MundeDas]

I was informed by my local independent Mercedes dealer that it is improbable that MB would cover the repair costs at no charge. The £175 is an initial investigative fee, which may increase significantly based on the required work and/or parts. Regardless, that's in the past, and any helpful suggestions would be truly valued 😊

[AmericaMonster]

The investigative charge can be limited by you, and in this case, I would have preferred a conclusive opinion from MB rather than your independent source, who cannot accurately predict what the outcome with MB might have been.

If that headlamp shows no signs of damage, it indicates a clear manufacturing defect.

Is the vehicle under a lease or financing arrangement?

[MundeDas]

I'm scheduled for an appointment with Mercedes, but I'm uncertain about how useful they will be if I've replaced the headlight on my own. It might be worth trying.

To my knowledge, there is certainly no damage to the headlight; it appears that the issue started during a recent period of inclement weather.

I fully own the car. It was purchased privately more than a year ago.

[AmericaMonster]

It's unfortunate in a sense that it isn't financed, as that would provide you with some extra leverage.

It is to be hoped that MB will act with integrity. 👍

[Captiva]

Regrettably, water ingress on electrical components is not covered under MB’s warranty. I received this information when my front parking sensors malfunctioned because of water exposure.

I had a replacement wiring loom installed at my local indie for under half of what MB quoted. 🙄

[MundeDas]

It's unfortunate, as one would anticipate their car to endure some rain. It's not a significant expense for Mercedes, and I suspect they handle much more serious issues under warranty.

[Kenjibb]

Even if the part codes are identical, the headlamps require coding.

[RacingNight]

I'm a bit late to this discussion, but please take a moment to review your arch liners. I’ve observed that on one side at the front, there is a small hatch, which I assume is for accessing the back of the headlight. On that same side, it appears to have dropped enough to create a gap in the plastic. Driving in the rain can lead to water being sprayed directly into the back of the headlight module, precisely where the ballast control modules are located, which over time may result in water ingress. This may not address your current problem, which seems to be related to either coding or a blown fuse, but it could help prevent a recurrence.