Stephen04E55

This procedure was not 100% necessary on my car. I felt with the car approaching 18yrs old it was time to replace. The fuel filter is located in the LH access as part of the fuel level assembly. The pump is located in the RH access. Neither of these parts were available through FCP Euro as they're listed as backordered. Parts Geek had both genuine MB parts in stock and they were identical to the ones I removed. 2094700494 (LH sending unit) & 2094700594 (RH pump) are the correct part #s

​​​​​​ ​Everything is accessed under the rear seats. Flip up the rear seats and remove the sound deadening felt. You will then see the two access panels which need to be removed. The center access panel is for the parking brake cable adjustment and does not need to be removed. The C55 has plastic retaining rings holding these units in place which is different than FCP Euro's video of another W203 6 cyl car. This is much like a W211. Gently tap the rings counterclockwise with a wide chisel wrapped with a microfiber rag to remove both of them and proceed to remove all electrical connections and the fuel line. I depressurized the system first prior to disconnecting the fuel line. Also, remove the fuel cap. The old units looked a little tired but not too bad considering. I have no way to judge the old fuel filter either. Replacing these two units was not difficult at all and once again I appreciate the engineering which did not require dropping the fuel tank. Pics below for reference. I may have skipped something but ask questions if something seems omitted.

Stephen04E55

a squirrel or whatever had placed a few snacks in the fuel pump recess...glad the thing didn't chew wires

ODB

thanks for posting this! I think I need to replace mine as well till parts still available. did you need any clamps for hoses to connect everything back?
Have you noticed any change in car's performance?

Stephen04E55

I did change the clamp which is for the fuel line inlet to the fuel filter. It is an oetiker type so I bought a cheap kit from Amazon to resolve that and keep it OEM looking. Otherwise the lines are all push/click type. I noticed no difference in performance however I didn't want it to be a problem as these items are considered wear items (especially the filter).

ODB

I wish you could just replace a filter and not spend ~$500 thank you!

miet.

Hi all,
Success using A211 470 39 94 from W211 E500 , which is much more available to buy

I thought I'll share some experience with my C55 fuel sending unit replacment
I was suspecting that the car is starving for fuel and it needs a fuel filer change,
but on the other hand I am such a tight *** that I thought I'll do more research regarding finding a cheaper OEM replacment.

My car had an original part still in with number A 209 470 01 41 (VDO part# 228 242 003 001) and I could only find the original replacements for approx. $500 USD
After browsing the web, I found out that my part was looking very similar to the the W211 part A211 470 39 94. This type does not have the pressure sensor - same as my C55.
I can see above that Stephen04E55 has the pressure sensor - which would correspond to the 211 470 40 94 part number ( I assume).

Not to spend too much money for the trail'n'error , I bought the cheapest A211 470 39 94 part I could find on Australian Ebay for 100 AUD shipped.
Part fits perfect and the fuel gauge seem to work without issues. Heights and dimensions seem to be identical to the OG unit.

The difference was in the overfill hoses diameter - the ones which are clipped on the top of the fuel pump housing bucket - W211 are bigger. Length seem to be the same.
Since I could not clip them, same as the original hoses were, I fixed them with zip ties. Purpose of those hoses is overfill and I think they'll work as designed.
There is chance that you could reuse the 'old' hoses from the C55 unit, but I thought it's not really required and I was afraid I'll brake some plastics in this process.
There is also a possibility to use a W211 E500 fuel pump 'bucket', which has bigger hose clap point, but I didn't had this on hand of course.

Happy over all , car seems to idle better and start a bit quicker too. I think it react on the throttle pedal quicker as well , but it may be subjective.
I'll clean the injectors now and she'll be all good then

Stephen04E55

since we're at the mercy of all of these parts interchanges (some of them are definitely incorrect concerning the w203 C55) do you think having pressure sensor versus not having the pressure sensor is any issue? I need to double check my old parts which I believe to be original and make certain that the part # markings are like yours. Thanks for the post and I believe this information to be invaluable as not much of it exists on the web.

brauhaus313

For us in the states, brand new OE prices for those 211 part numbers are more expensive than the correct part numbers for our C55s. FSU's seem to be still pretty available from dealer websites. If supply dries up, the W211 part number could be helpful.

Kamui

Interesting post.
I would have done a pressure test before replacing the unit. Also, depending on how many miles it has, it could be the case that bad fuel might have cause a blockages at the filter. Unfortunately, these filter are not replaceable from what I understand, leaving people to buy new pumps (units). I replaced mine close to 10 years now, no issues (direct OEM from Benz).
Hope you don't run into issues. Just keep in mind that fuel tank environment necessitates proven materials. If you install anything that is not an adequate material for that environment, you might be shooting yourself on the foot.
Thanks for posting

Stache

I replaced both pumps in my 2006 C55 and later the fuel gauge started to read full all the time. I found this in GF54.30-P-3018PM:
Fuel tank sensor tight installation recognition
[After a] travel distance of greater than 160km the fuel tank sensor tight installation recognition becomes active. Tight installation of the fuel tank sensor is recognized, if the resistance value of he left tank half fuel level sensor (B4/1) and/or the right tank half fuel level sensor (B4/2) does not change by at least a specified resistance value within a certain distance.
Indication: ...the pointer moves to the beginning of the scale and the fuel reserve warning light does not come on.

My fuel gauge now shows full all the time and there is no warning light. After over 100 miles, an analyzer showed both tanks as being full.
The level sensor on my left tank has remained at near 51ohms while the sensor in the right tank is variable. Pump was installed with correct alignment.

I am open to suggestions and have checked both installations. Bad sensor on the pump?

Stephen04E55

so my car now has the same condition and the fuel gauge is now stuck on full. this is just in the last few days and the fuel pump and filter sending unit have been operating for 2000+ miles. I did track the car once and this is exactly when the fuel gauge started misbehaving. I'm working on a resolution now but I haven't had any energy to take the thing apart again.

Rahulio1975280C

Hello Stephen,

I want to replace the fuel filter and fuel pump in my 2005 C55 AMG with 168K miles while parts are still available.,

Were you able to figure out what happened to your fuel gauge?

Thank you

Stephen04E55

yes...the float was loose and turned which required nothing more than a reposition and snap back in place. I didn't trust it so I actually replaced both of the units again. It has been at least 3,000 miles now and no problems whatsoever. I ordered the parts this time from Mercedes parts through a dealership and they are the same part numbers listed above. Good luck with your car.

WadeBrookss

thanks for posting this! I think I need to replace mine as well till parts still available. did you need any clamps for hoses to connect everything back?

Stephen04E55

only the little clamp (oetiker style) from the output of the pump on the driver's side. The other ones are "push and snap" type which are meant to be reusable. It is still working great! 4K miles on the new pump