C55 Bi-Xenon Lights Problem
Thread Starter
MBWorld Fanatic!
Joined: Feb 2004
Posts: 1,001
Likes: 37
From: NY
2014 E350 4Matic
C55 Bi-Xenon Lights Problem
Hi guys,
I searched around here but did not find an answer to my issue. Right now, my passenger side Bi-Xenon light works just fine most of the time after I start the car. But, every once in a while the passenger side light just won't come on and will through a an error "right low beam". The high beams always work and after I shut the car down and restart it, the passenger side light works fine. I have new bulbs in both lights and checked the connections best I could, the bulbs are firmly attached.
Anyone know what could cause this? or what the solution is?
I searched around here but did not find an answer to my issue. Right now, my passenger side Bi-Xenon light works just fine most of the time after I start the car. But, every once in a while the passenger side light just won't come on and will through a an error "right low beam". The high beams always work and after I shut the car down and restart it, the passenger side light works fine. I have new bulbs in both lights and checked the connections best I could, the bulbs are firmly attached.
Anyone know what could cause this? or what the solution is?
Member
Joined: Jan 2013
Posts: 241
Likes: 1
From: Edmonton
2003 C32 AMG
Yes, there are two culprits at this point. There is a headlamp control unit for each side.. they are small silver boxes and control the ignition of the xenon bulbs.. it is very very common that water works its way down there and you end up finding these things corroded. To diagnose this issue, you need to swap the control units left and right (they are the same) and see if the issue follows. If it does, you need to replace the module.. They can be found online for between $200-$500 new.. a lot of used ones for sale and I actually have a spare I'd be willing to sell you if you find out that this is the problem. If the problem does not follow with the control unit swap, then the problem is with the igniter itself. (this is the red plug that the bulb connects to) and it runs down into the headlamp assembly. Mercedes Benz sells a repair kit for the igniter where you cut out the old one and solder in a new one. It is expensive though, and around $400 dollars. (last I checked from the dealer). So, there you go. If all else fails (very very unlikely) then the issue lies with the computer that controls the headlamp modules (the SAM) and since you have no other issues I wouldn't worry.
Long story short: swap control units left and right, if not its the igniter (since you said the bulbs are new)
From Mercedes Benz:
Complaint
Xenon burner does not ignite or flickers
Cause
Transistor in xenon headlamp control unit (E1n1/E2n1) defective.
Complaint
Fault message in IC ( instrument cluster) "check left/right low beam bulb" High beam and/or low beam sporadically nonfunctional
Cause
Xenon burner (SSL: 82126 73)
Xenon control unit/ignition module (SSL: 82119 73)
Long story short: swap control units left and right, if not its the igniter (since you said the bulbs are new)
From Mercedes Benz:
Complaint
Xenon burner does not ignite or flickers
Cause
Transistor in xenon headlamp control unit (E1n1/E2n1) defective.
Complaint
Fault message in IC ( instrument cluster) "check left/right low beam bulb" High beam and/or low beam sporadically nonfunctional
Cause
Xenon burner (SSL: 82126 73)
Xenon control unit/ignition module (SSL: 82119 73)
Last edited by Supgee; Dec 11, 2014 at 08:24 PM.
Thread Starter
MBWorld Fanatic!
Joined: Feb 2004
Posts: 1,001
Likes: 37
From: NY
2014 E350 4Matic
Thank you Supgee and Viper for your detailed analysis and recommendations. I will swap the ballasts (i.e. control units) at my earliest convenience and see what happens. However, these headlights, ballasts , igniters, etc. were replaced about two years ago and are therefore relatively new (about 40k miles worth).
Member
Joined: Jul 2010
Posts: 143
Likes: 9
C63, C55 (sold), 2002 C32 (sold)
Hope all is well. I am currently having an issue with my headlights, I think it seems to be the ballasts on both headlights. May you please elaborate on how to replace the ballasts? Is it a fairly simple DIY job? Would appreciate your input.
Thanks,
MBWorld Fanatic!
Joined: Jun 2009
Posts: 3,040
Likes: 125
From: Atlanta Metro
Current: C217 V12TT AMG Previously: C55 AMG, SL65 AMG
When I first replaced my ballasts, I did it by removing the headlight upward and flipping over (the ballast is underneath). To remove the headlight, you not only have to remove the top bolts, but there's also a side bolt behind the bumper (near where the fender meets the bumper). So to remove the bumper (or at least, enough forward so it's out of the way), you need to take off the front grill, additional bolts, and fender liner. There's also a clip that holds the fender to the bumper, and it has a pivot point and additional bolt that you need to figure out once you're messing with it.
The ballast itself is held on by three bolts, and once you unbolt it it slides off. You'll see that the internal connector is actually mounted to the headlight, and the ballast just goes into it. So there's no connector to remove, technically.
Now, the last time I was poking around I think I figured out that there's enough clearance underneath the headlight where you could go in through the fenderwell and not have to remove the headlight at all. So I suggest taking off the wheel, taking off the fender liner, and seeing if you can reach a tool in there to pull down the ballast. If yes, then the process is so much easier.
The ballast itself is held on by three bolts, and once you unbolt it it slides off. You'll see that the internal connector is actually mounted to the headlight, and the ballast just goes into it. So there's no connector to remove, technically.
Now, the last time I was poking around I think I figured out that there's enough clearance underneath the headlight where you could go in through the fenderwell and not have to remove the headlight at all. So I suggest taking off the wheel, taking off the fender liner, and seeing if you can reach a tool in there to pull down the ballast. If yes, then the process is so much easier.
