I bought a 2011 s550 which was involved in a minor collision affecting the headlights. I'm now trying to bring all functions back to proper working order.

The headlight switch is the version with a single fog light pull step. When I pull it, the rear fog light activates.

Question is, what should happen on the front? The manual talks about fornt fog lights but does not identify them on the vehicle.

Could someone let me know what lights come on on the front when you pull the switch?

 

did u try a second pull ?

front fogs usually on the bumper

 

No, there's only one pull stop possible. I was surprised, as any mercedes I've had had the fronts on the first pull and the rear on the second.

But on this one there's only one stop and it activates the rear.

 

for rocket scientists they do this thing called a user manual.... the symbols here got messed up to silly characters

Fog lamps
Fog lamps cannot be switched on with the exterior lamp switch in position Auto or OFF

Warning!
In low ambient lighting or foggy conditions,
only switch from position A to On with
the vehicle at a standstill in a safe location.
Switching from A to On will briefly
switch off the headlamps. Doing so while
driving in low ambient lighting conditions may
result in an accident.

Front fog lamps will operate with the parking
lamps and/or the low-beam headlamps on.
The rear fog lamp can only be switched on
with the exterior lamp switch in position
On. Fog lamps should only be used in
conjunction with low-beam headlamps.
Consult your State or Province Motor Vehicle
Regulations regarding permissible lamp
operation.
X Switch on the ignition.
X Turn the exterior lamp switch to position
T or L (Y page 298).
Vehicles with front fog lamps
X Switching on front fog lamps: Pull out the
exterior lamp switch to first stop
(Y page 298).
The green indicator lamp N in the
exterior lamp switch comes on.
X Switching on rear fog lamp: Pull out the
exterior lamp switch to second stop.
The rear fog lamp, the front fog lamps, the
green N and the yellow indicator lamp
R in the exterior lamp switch come on.
X Switching off front fog lamps/rear fog
lamp: Push in the exterior lamp switch to
its stop.
38 When the parking lamps are on, the tail lamps, the license plate lamps, the side marker lamps, and the
instrument cluster illumination are also on.
300 Lighting
Controls in detail
Vehicles without front fog lamps
X Switching on rear fog lamp: Pull out the
exterior lamp switch to its stop
(Y page 298).
The rear fog lamp and the yellow indicator
lamp R in the exterior lamp switch
come on.
X Switching off rear fog lamp: Push in the
exterior lamp switch to its stop.
Locator lighting and night security

 

either this car or this headlight switch never had front fogs

excerpt from the 2010 facelift user manual

 

Thanks @BOTUS , I've gone through the manual and was surprised that there's talk about front fog lights, but there is no pixelated black and white picture with a little arrow pointing to the specific light. So, to reiterate my question, which is not answered by the manual:

If your facelift 221 has front fogs (two-step pull of the switch), what light source comes on on the front when you activate them?

 

they did seem to play

I thought the LED lights around the bottom of the 2010 model year main headlight units were the DRL (day time running lights), but with LEDs on the bumper I guess they are just the side lights ?

front fogs were always below the bumper on the 221 - as they should be on any car - the idea is for front fog lights to see beneath the layer of fog, to illuminate the road without flaring up in the drivers eye (for when we have actual fog with no visibility at 30 foot), hence why they can't operate in the Auto position (especially on the later car's with high beam assist)

Merc do like to play silly buggers with if this doesn't work (bulb failure) we'll turn this on instead.... so vice versa may well be possible

it does look like the facelift 221s got LED running lights below the bumper...

user manu is useless in this regard - with no decent photo of the cars showing features

early car with front fogs on the left, which are also the DRLs - on the right DRLs on (can't see them being much use in fog)

 

I did find out how they work, so I'll put it here, in case anyone is interested. It's a bit sad that the 221s apparently have mostly passed from enthusiasts into people only interested in cutting exhausts and fitting 23"s. But that's the way the world goes.

On facelift vehicles, the front fog light function activates full brightness on the bumper led strips, AND dips the low beam a little bit (lighting up less distance, but also producing less glare).

 

These cars do not have separate fog lights. The led strip low on the bumper is the DRL and when fog lights are activated these lights turn completely OFF.

DRLs are made to be bright and emit light is wide angle to make car as visible as possible to other road users in daylight conditions. These lights would completely blind the driver in foggy conditions, so these lights turn OFF with fog lights activated.

Fog light function is built-in to the head lights and if this function is activated in the car's coding the head lights dip down to the lowest distance and the driver's side light also turns sideways so widening the fog light beam.

I used to have a 2011 E350 with the Bi-Xenon lights. This car had a main light switch with Auto position with a button for fog lights next to it. If I was driving with Hi-Beams on and pressed the button the head lights automatically turned to low beams and to the lowest distance and widened the driver side light to left and, of course, turned the rear driver side fog light ON.

With my 2012 S550 I have the driver side light in front widening but if I have Hi-Beams selected they do not automatically switch to Lo-beams nor do I see light dip down. This same is the case with my 2010 E550 that does not have the button like the 2011 E350 had.

In all of the above-mentioned cars the DRLs turn completely OFF when fog light function is selected so if your car has the led strip like is shown in the right side picture in BOTUS's post and the car keeps these DRLs ON with fog lights then you have a malfunction with your lights.

The basic principle with fog lights is to keep light beam angled down so the light does not reflect back up to driver's eyes in fog and this is why DRLs must be turned OFF as these are made to do exactly opposite compared to the fog light beam.

 

I need to correct my post a little bit: My head lights do move down to shorter distance when I put the fog lights ON but the HI-beams do not automatically change to LO-beams.