shanken250

I'm starting to think I'm nuts. I need to replace the fuel pump on my 2001 C320. I ordered one taking carefull account of my VIN number as it relates to the multiple options available. I get the new pump and it is identical in every way except the electrical connector. The new one is 4 prong in a square pattern, 2 on top and 2 on bottom. The connector on my car is also 4 prong but in a straight line. I cannot find anyone to tell me what type of connector will be supplied on a new pump. Is there an adaptor made for this application or did I get the wrong pump and there really is one out there that fits out of the box?

Thanks for your help,

Scott
2001 C320
Portland, Oregon

splinter

Sanity is certainly not a requirement to participate around here...they haven’t kicked me out yet.

MB and other manufacturers frequently change parts throughout the model run and often, unfortunately, during the same year. Please, do not use an adaptor or attempt to jerry-rig such a safety critical part. Where did you get the pump? If it was via mail order, get on the horn pronto because electrical parts are invariably non returnable. He messed up, so you should not be culpable. My parts guy is pretty good about supplying the proper part first time ‘round. You weren’t so lucky, VIN or otherwise. On a piece such as yours, I’ll head to the parts counter with the old one in hand and ask, “I’d like one of these; would you please?” If it came from a local vendor, appeal to his sensibilities and principles face-to-face.

In the spirit of full disclosure, I haven’t yet personally done the pump replacement . When mine fails, the entire tank must be replaced, necessitating the expenditure of almost a week’s income...so don’t feel too bad! What is the part number on your new one? I'll check it in the catalog to see if it's even close to being the correct part for your application.

SeaCoupe

You are in good hands with Splinter. He is certainly right on the safety aspect. Get it switched out. I think this is a simple problem from the parts puller who grabbed the wrong box. If you got it dirty or greasy, clean it up, and send it back.

E

shanken250

It was an internet order (alloemautoparts.com). I'm a pretty good mechanic and splicing wires or any other kind of jerry-rig with a part that spends its life surrounded by explosives didn't even cross my mind. The part number from the supplier is E3000-231812, I assume this is the Bosch number but I'll check in the morning and post the number on the part itself (the fuel pump is at my shop and I'm home)

Thanks for the help,

Scott

marksinger33772

The pump gave out on my 240 a while ago. The pump has been upgraded by Mercedes, and the plug on the new one does not match the old setup. My tech had to replace the pump and both sending units in order for the plugs to match. Hope this helps.

shanken250

The part number for the new pump is: A203 470 35 94

I attached some pics of the old pump and the new one so you guys can see what I'm talking about.

marksinger33772, does this look like the same issue you had?

Once again, thanks for taking the time to help me out.

Scott

splinter

Please forgive the delay in getting back with you.
I’ve been away from my good computer's HD stash and its access to MB's EPC.

The 203 470 28 94 pump was used in the US/Canada chassis before #188244, or those built prior to 9/28/2001. Does that look at all familiar on your old pump? It has indeed been superceded by the 203 470 35 94.

Call or visit an accommodating dealer to see if by chance any 203 470 28 94’s remain in the distribution warehouses. The alternative will run about $250 in addition to the pump you have already acquired. In order to install the new 203 470 35 94 pump in a early car requires the use of a 203 470 29 41 sending unit ‘mounting plate.’

marksinger33772

Yep, exactly the same problem. Splinter knows what he's talking about. Get this, my independent shop charged over $700 for this repair, also due to the fact he had to replace both sending units. Couldn't fix it myself, since the car was sitting on the wrecker after konking out on my way to work.

shanken250

splinter,

Thanks a bunch, I'm on the right track now.

I really appreciate everyones help.

Scott

PS: marksinger33772, $700.00 doesn't sound all that bad, I'll be into this $500.00 just in parts.

Ken1969

I am having the exact same problem with my fuel pump... Dang connectors! The original part says 203 470 13 94. I have the flat four prong that looks like the pics taken above by shaken250.... Anyone have any suggestions where to find the pump only? HELP!

SeaCoupe

It is a great little scam is it not? Change the connectors and then you have to buy both pumps.

If you take my info and act on it, you are acting on your own responsibility. Worrking around gas fumes is DANGEROUS! Know what you are doing.

I cut off the connectors on the harness and on the new pump. I then put spade lugs of the appropriate size on to match the male terminals of the new pump. Then I put on terminals for the float level sensor. These have to be quite a bit smaller.

Your pump will likely show you which is the postive and negative terminal. Test to insure you know which lead on your harness is the positive and which the negative. The connect everything. The Float level wires are both blue, and I don't know how to test for the correct connection, but hell it is a 50/50 shot.

Carefully reinstall and you are in business.

I have been driving my car like this for almost a year. I was a bit nervous turning it on for the first time, but really, I have not had an issue.

Ed

Ken1969

Thanks Coupe! . I'll check it out to see if i can do it. How did u attach the old connector to the new pump? Or does it matter?

Ken1969

I may end up going to the Benz salvage yard and just replacing them both for less than $125. Heck, for both parts at the local parts store they want over $650. If the used ones go bad, I can change them 4x before i would exceed the cost of a cost new set. Lol. I will let you know on whatever I do...

Ken1969

Hey, thanks to you all for the input on my delema! I finally got a used pump from a salvage yard for $75 and just swapped out the fuel level sending unit from my broken fuel pump to the new (used) one. Zipped tied the connectors to the new unit and installed. Turned the key a couple times just to prime the system and it started up the first time! Runs better than ever!

From all the folks that helped me at the autoparts store, Mercedes dealer, local mechanic, etc, etc, this problem only has happened on the early 2001 model c240 or c320...

I hope this helps someone who is getting as frustrated as I was!

WaveyKat

Was going to start a New thread but I will just added here:

will today I replaced the fuel pump from my 2002 C240. I purchased a USED pump From EBay from a 2003 C320 thinking I would have gotten the same pump & Sending Unit and wiring but I was wrong.. the fuel pump in the 02 C240 connection was a 4-pin in a box and this one I got was 4-pin in a straight line (But not like the above Pictures).. the sending unit (Driver Side) from the 03 C320 had a 4-pin in a straight line but the "power connector" where it plugs into the car power was a 5-pin in a straight line and my 02 C240 was a 4-Pin Power Connector.. hope that makes sense lol..
anyway what I did was remove the wiring harness & level sensor from the old pump "02 C240 (Pass Side)" and wire it to the USED "03 C320" pump (Pass Side) the connector to the pump are also different smh so I had to cut the connector off and add some splicing.. but so far it works..

here are some pictures" of the 02 C240 fuel pump taken apart. I think the fuel pump "Silver Part" can be purchase and installed in the casing to save LOTS of money..

SeaCoupe

Nice work. You certainly can splice in the correct connector. I just connected female spade plugs and all was well. I will admit, I was a bit nervous driving the car the first mile or so.

Nathan Poer

Ok I have a 2002 c230k coupe with the 6 speed. Had the exact same issue as described.
THE FIX: take your old sending unit and attach it to the new pump assembly it will hook up totally fine except you will have to safety wire or zip tie the 4 prong flat connector to the new pump.
WHAT IF SENDING UNIT GOES BAD: Take your new sending unit and pump assembly to the work bench and solder the wires together using high quality heat shrink to seal.
Hope this helps!!

Nathan Poer

Ok I have a 2002 c230k coupe with the 6 speed. Had the exact same issue as described.
THE FIX: take your old sending unit and attach it to the new pump assembly it will hook up totally fine except you will have to safety wire or zip tie the 4 prong flat connector to the new pump.
WHAT IF SENDING UNIT GOES BAD: Take your new sending unit and pump assembly to the work bench and solder the wires together using high quality heat shrink to seal.
Hope this helps!!

mhd_bill

I have the same problem Splinter, are you sure that this solution of upgrading the sending unit to 203 470 28 94 will enable me to use 203 470 35 94?

C230 Sport Coup

You'll probably need to PM Splinter. Not sure if he's still on the forum, but I think he's long
gone from the W203 forum. I'm like the last of the OG.
I did my fuel pump a few years ago...guess I got lucky.
Mines a little older than SeaCoupe's. I'm like 12/2001 and his was an early I think 6/2001