I have a message that reads: Low Left Headlight" How can I repair, is it a fuse

I am responding to this as an E350 owner only. Since this vehicle is about 6 years old I suspect it is a burned out bulb; mine was. If you are going to replace it ensure the bulb you purchase is the one cited in your manual, mine was an H7 type. Remember when replacing Halogen bulbs to never touch the glass envelope with your bare fingers. I typically use a thin latex glove and even then stay away from touching it. NOTE: YOUR USER MANUAL WILL ALSO HAVE THESE INSTRUCTIONS. I am not a professional mechanic; but I am somewhat experienced in performing such minor tasks on the different Mercedes I have owned. However, although this was straightforward I found this one to be more challenging because of the confined space. I would first do a dry run and just reach into the work area to see, because of the confined space, if you will be able to do this. To replace your Low Beam bulb: With the hood raised and some good light on the back of the headlight assembly area, refer to your manual: 1. Remove the flat, black plastic cover (housing) turning it counterclockwise. This exposes the back of the bulb assembly mounted in the light enclosure. Note: Important to remember exactly how you remove the bulb as this is also the manner in which you will need to replace it. Try to remember also how it feels coming out. 2. Very carefully turn the bulb assembly to the left (counterclockwise) and when loose slowly remove it from the light enclosure. 3. Carefully pull the bulb out of the bulb socket. Note: it may be a little difficult but be patient and it will come out. 3. Very carefully insert the new bulb into the bulb socket not to touch the glass envelope. Here is the difficult part. As you noticed there isn't much room to work in the space provided. Even with light you may need to insert the bulb back into the light by feel alone. 4. Slowly and carefully place the new bulb back into the headlight and slightly press and turn clockwise until it engages. When I did mine I had a difficult time getting it to engage. Make sure you place it flush and evenly up against the socket when you turn it. Note: I found that this was a very confined space unless you remove the headlight assembly. If I had to do it again I would consider removing the small radiator tab on top of the reservoir, and move it over, to give me more space to work. Caution: It is up to you on how comfortable you are with this and your knowledge of cars. Hope this helps. If you do not feel comfortable with this I would have a local mechanic you work with replacing the bulb for you.

No, its not fuse- and Yes, the dealer may charge a stiff fee for this service. Find a local MB or european vehicle independent garage to take care of that for you- should cost a little less.

Allow me to add these thoughts to the near perfect answer presented by "motor137". After you remove the light housing protective cap, set your cell phone video camera to "flash-on and slo-motion" so you can more completely "see/understand" that which you will be "feeling." Additionally, the reservoir was just a bit too much in the way for my arm/hand movement. So you can free-up a couple of inches by removing the clearly visible nylon Rivet (MBZ part no. 124-990-04-92) holding firm the reservoir. I did it by slowly grinding off top of rivet with larger drill bit. The rivet was under $4.00 at MBZ and I suspect cheaper elsewhere because it seems generic. Finally, the top-of-line halogen replacement bulbs, i.e. H7 Sylvania SilverStar Ultra, have a lessened life (from standard bulbs) because they burn at a significant temperature: Keep your proof-of-purchase receipt because I understand Sylvania will honor and replace if there is failure within 12 months.