I guess you are referring here to the activated charcoal filter - part of the a/c system. Looks like they come as a pair. There is also a dust filter located in the engine bay, over the battery. Unclip 3 catches to remove.

To change the charcoal filter, first remove the panel under the glove box by taking out the 2 screws. The filters are located next to the a/c blower. The drawing below will help.

 

After-thought here.

Your smell might not be caused by the charcoal filter. Sometimes the a/c system blows bad air due to mildew growing inside the ducts. You can kill it with a suitable spray.

See many posts on Google on this topic: eg,

ac - Why does my A/C blow foul smelling air when it first turns on? - Motor Vehicle Maintenance and Repair Beta - Stack Exchange

 

When I start my car (2004 CLK320), I can smell something from the ventilation. After the drive for a few minutes, the smell will go away. This happens even before I turn on the AC.

I don't recall ever changing these "activated charcoal filters". Strange, my car has been maintained by the dealership for many years, they never mentioned this.

 

carbon cabine filter change

THANK YOU FOR THE REPLIES,YOU HAVE BEEN VERY HELPFUL.I WILL CHANGE THE AC ACTIVATED CARBON FILTER,(THANKS KEYHOLE),AND WILL SPRAY LYSOL IN THE DUCTS,I WILL POST RESULTS,THANK AGAIN

 

Just an FYI, posting in all caps is difficult to read and is consider "screaming" at your audience.

 

Hold on!

I recently ordered an engine bay cabin air filter only to receive an inexpensive paper pleated filter without the charcoal my OEM filter has. I had to reorder a charcoal one so wasted the money on the first. This is the filter over the battery on the passenger side firewall (209).

Yesterday, I ordered one (1) carbon filter for under the glove box. But I see from the pictures you posted that it seems to require two (2) filters? Is that correct? There are a total of three (3) activated charcoal filters for the cabin air?

If so, I need to order the second one for under the glove box.

For mis3, you might be happy the dealership didn't replace those filters as it might have been an arm and a leg like most things they do outside of warranty. ;-)

 

Yesterday, I ordered one (1) carbon filter for under the glove box. But I see from the pictures you posted that it seems to require two (2) filters? Is that correct? There are a total of three (3) activated charcoal filters for the cabin air?

If you order air filters for the engine, they come as a pair. Similarly I would expect the activated charcoal filters to come as a pair. The paper a/c filter, located over the battery, is shown here when unclipped from the intake duct (on my RHD CLK)

 

This is my understanding:
Above the battery: Pollen filter 203-830-09-18
Behind the glove box: Charcoal filter

Can someone please provide the part number of the charcoal filter?

 

What if all 3 filters are changed from the pollen compartment?

 

Charcoal filters for code 581 climate control P/N A203 830 21 18

 

I am afraid to remove the glove box.
I broke the hinge last time I removed it.

 

Question remains...

Let me boil it down:

Are there two (2) activated charcoal cabin air filters under the glove compartment IN ADDITION to the carbon cabin air filter above the battery in the engine compartment?

The picture, Number 1, has two arrows pointing to what appears to be two filters and instruction #3 says "Pull out both activated charcoal filters (1) from below."

I am referring to the PDF file in post #2.

 

Let me boil it down:

Are there two (2) activated charcoal cabin air filters under the glove compartment IN ADDITION to the carbon cabin air filter above the battery in the engine compartment?

The one above the battery is NOT a carbon filter - it's just paper as my image shows. Under the glove box are a pair of activated carbon filters.

Incidentally, before you pull off any panels, be advised that not ALL a/c systems have an activated charcoal filter. Check the unit front panel to see if you have a push-button there to switch it ON/OFF, as shown on my a/c panel below. (left side, to the right of the red UP arrow)

 

Mercedes Benz Parts
enter part number 2038302118
you can see on diagram 2 charcoal air filters #22

 

I talked to the parts department and he said that not all w209 have the charcoal filters. Is this true?

 

That is correct - only the models with the "full dual-zone" A/C have the charcoal filter. If all you have is dual temp control, but not dual airflow control, you don't have the charcoal filters. I believe the full dual-zone A/C system came standard on V8's but optional on V6 models (at least in the USA). Oh, and you will have a button to activate the charcoal filter. If you look at Keyhole's picture above, it's the button just to the left of the LCD panel that has the symbol ">|>" on it.

 

Is this the button that would close all the windows?

My car does have the dual-temp control. So, I do have the charcoal filter then. After 250K Km, I should probably change them.

The filter change and the "mist" procedure (to clean the ventilation system) will cost $300.

 

Just read the manual, I do have the button called "Activated charcoal filter". So, I do have the charcoal filter. I usually use this button to close the windows and sunroof fast.

I did not know that the Air Recirculation button closes all the windows as well!

According to the Service Booklet, these filters should be changed every 100k km or 5 years. I guess I should change them soon. I called a local Toronto dealership, this part costs $165 CAN (sales tax included). I then called an US dealership, the same part costs $78.

 

Check the details below. CLK's with the system on the left do NOT have the activated charcoal filter. Those with controls on the right do. The button inside the right-hand control ring, above the small vent slats is the button that turns on the charcoal filter.

 

My climate control system does not look like this at all. Probably it is a Canadian version.

When I called the two dealerships, they both confirmed, from my VIN, that I have the charcoal filters.

 

Oops, sorry, you have a MY2004 which is pre-facelift. Does yours look like one below? If so, then you do have the charcoal filter (button #4). If you don't have that style control, then you don;t have the charcoal filter.

 

Yes, this is the one.
Thanks.

Are these filters easy to replace? Are the filters behind or beside the glove box?

 

Price reduction at dealer for 203-830-21-18

I spoke with my M-B service rep and he told me my filter part numbers are 203-830-21-18 which confirms a posting above.

He also told me he thought I could do it myself without difficulty.

More importantly, he told me that the filters had been redesigned and repriced from $71 to $53 so not to be overcharged at the parts counter.

What wasn't clear was whether this was for EACH filter or a package of two. My 2008 CLK350 has the "tunnel mode" button that closes everything and diverts to the activated charcoal cabin air filters. I will attempt to post a pic of my controls.

 

My climate control module is the one in post #22. There is a button to turn on and off the charcoal filters.

Both dealerships said they came in pair. The US dealership yesterday told me it's $78.

I think you can change the filters by removing the panel below the glove box.

 

There is a button to turn on and off the charcoal filters.
Both dealerships said they came in pair.
I think you can change the filters by removing the panel below the glove box.

Isn't that what I said in posts #2, #8, and #13..? :thumbsup:

 

In local Toronto dealerships,.they call the dust filter on top of the battery the "pollen filter" and the one below the glove box the "charcoal filter". They are basically all dust filters.

I did not know about this charcoal filter until I read this thread. I have this car for 8 years and I change the pollen filter regularly, about once a year. I don't believe that the charcoal filters was ever changed, I better replace them soon.

There is also another charcoal filter in the back for the fuel tank. This one was replaced by the dealership under warranty when my car was 2 years old.

 

I did not know about this charcoal filter until I read this thread. I have this car for 8 years and I change the pollen filter regularly, about once a year. I don't believe that the charcoal filters was ever changed, I better replace them soon.

There you go... just shows how useful this forum is... But why not remove them & check their condition before you order new ones.

There is also another charcoal filter in the back for the fuel tank. This one was replaced by the dealership under warranty when my car was 2 years old.

Yes, that's the activated charcoal canister, located behind the right rear wheelhousing liner. It's in the fuel system purge line. (required in the US - not in the UK/Europe)

 

I already asked my friend in New Hampshire to buy the charcoal filters for me. It will cost me $78, rather than what they charge here in Toronto, $165. I will see him next week in Montreal.

I will then visit my indie afterward for front brake change, oil change and also replace this filter. I also asked him to get me an oil filter ($16.5 vs $28 in Toronto).

My indie is a Sprinter specialist and he just started to service MB. I am not sure if he knows about this charcoal filter. He started to service my car only since Feb-2012 for the ATF pan flush. He is very knowledgeable in 722.6 because Sprinters also have the same transmission.

 

I will be changing the charcoal filter in 1-2 weeks.
My question is should I spray some air freshener around the filters?

 

I guess, if you want the smell of air freshener in your car.

 

Keyhole - you stated - "If you order air filters for the engine, they come as a pair."

If you are ordering K&N filters, you will need to order two. That's what I has to do.