Greeting MBW
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GLS 4th450. 2020
Greeting MBW
I joined some time ago but never used the forum. I have a 2020 GLS 450 and one headlight all four turning signals and one break light have gone out. Mercedes says it due to moisture in the lamp. My SUV has never been in an accident and they is water collecting in all four light housings. at the seal there are cracks that have let water in. I need to replace them, but it is going to cost me 8 thousand dollars. Found some after-market as well as OEM parts but I am not sure I can replace them myself. Any advice or suggestions as I read on google says they won't work due to needing to be programed. PLEASE HELP!!!
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Joined: Nov 2023
Posts: 132
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From: Michigan
22 GLS 450 19 CLS 450
I joined some time ago but never used the forum. I have a 2020 GLS 450 and one headlight all four turning signals and one break light have gone out. Mercedes says it due to moisture in the lamp. My SUV has never been in an accident and they is water collecting in all four light housings. at the seal there are cracks that have let water in. I need to replace them, but it is going to cost me 8 thousand dollars. Found some after-market as well as OEM parts but I am not sure I can replace them myself. Any advice or suggestions as I read on google says they won't work due to needing to be programed. PLEASE HELP!!!
Alternatively you could punch a hole in the lamp with a hammer and file a comprehensive claim with your insurance company. Not the most honest solution but I feel like charging you the equivalent of a decent used car for a headlight replacement isn't super honest either.
Also, all of these issues are most likely caused by a single lamp and their modules, not all 4 corners. When my one light and two modules went it caused all sorts of light problems across the entire car. Finally, if you are able to get the dealer to just charge you to activate the modules I would strongly suggest biting the bullet and replacing both headlights at the same time. If the seals are going it's only a matter of time before you end up with the same problem a second time. Best of luck, I truly feel for you. Getting this resolved sucked and blew and not the fun way of either.
Last edited by mike7513; Jul 21, 2025 at 06:25 PM. Reason: grammar
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Joined: Dec 2019
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Unfortunately, the internet is correct in this case. I had an issue with a right front headlight on my 2022 450 several months ago and it was a huge headache. Once water gets into those modules that's a wrap. The good news is you can source an OEM lamps and OEM Modules from eBay fairly inexpensively but the modules are locked and you will need a dealer to provide that service. I would contact your MB dealer or several dealers and see A) if they will do this for you and B) what they will charge you. If you can get them to do the coding for you, you should be able to get the lamp and the modules you need for under $1000.
Alternatively you could punch a hole in the lamp with a hammer and file a comprehensive claim with your insurance company. Not the most honest solution but I feel like charging you the equivalent of a decent used car for a headlight replacement isn't super honest either.
Also, all of these issues are most likely caused by a single lamp and their modules, not all 4 corners. When my one light and two modules went it caused all sorts of light problems across the entire car. Finally, if you are able to get the dealer to just charge you to activate the modules I would strongly suggest biting the bullet and replacing both headlights at the same time. If the seals are going it's only a matter of time before you end up with the same problem a second time. Best of luck, I truly feel for you. Getting this resolved sucked and blew and not the fun way of either.
Alternatively you could punch a hole in the lamp with a hammer and file a comprehensive claim with your insurance company. Not the most honest solution but I feel like charging you the equivalent of a decent used car for a headlight replacement isn't super honest either.
Also, all of these issues are most likely caused by a single lamp and their modules, not all 4 corners. When my one light and two modules went it caused all sorts of light problems across the entire car. Finally, if you are able to get the dealer to just charge you to activate the modules I would strongly suggest biting the bullet and replacing both headlights at the same time. If the seals are going it's only a matter of time before you end up with the same problem a second time. Best of luck, I truly feel for you. Getting this resolved sucked and blew and not the fun way of either.
