W211 E55 fuel tank replacement. Verify parts!
 

For those who had or will have the fuel tank replaced in their car, verify the fuel pump adapter cable is installed!

Been going back and forth with another member of the forum having issues with the fuel supply. Fuel tank replaced under warranty. He sent me a photo of the top of the fuel pumps and the adapter cable was missing. This now makes two confirmed instances (BoostedAero and this other forum member) where the fuel tank was replaced but the adapter cable was not installed. Easy mistake to make as the connector on the original harness matches the new fuel pump connector. The problem is the original harness in the car has power (striped wires) on pins 1 & 3. The new fuel pumps provided with the tank have power on pins 2 & 3. The adapter harness swaps the connections. If you do not use the adapter harness, one of the pumps runs backwards, fuel pressure will drop at wide-open throttle and high rpms, potentially lean air:fuel mixture with chance of detonation and damaged/destroyed engine. The adapter cable is a must with fuel pump P/N 211-470-00-00. You can read the part number on the top of the fuel pump.

See attached photo to see how to confirm installation. Remove rear seat, open the lid over the fuel pumps on the right-hand side. Also, look to see if the foam insulator was installed on the underside of the metal lid; that is intended to prevent the power wires to the fuel pumps from shorting out against the underside of the metal lid.

thanks for the details on this and your other fixes for fuel pump relays/fuses ,, I am going to have to do some work now that the weather is starting to cool down - you may never have know that this was messed up until its too late and done some major damage

This is an issue I am dealing with now. I will go in to more detail later, but if your harness was not replaced, bring it to the dealer and have them replace and make sure the tech who worked on your car gets written up for not replacing parts when they should have. This issue will cause the pumps to run AGAINST each other during higher rpms, 1 pump will feed the rail and the second pump will pull away from the rail and cause the #8 cyl to starve.

Does anyone have a part number on the proper adapter cable?

211-540-07-00. About $15.

https://login.i.daimler.com/internet...and=aftersales

http://aftersales.mercedes-benz.com

how do we sign up...it seems if you have a classic Benz you are given free access after registering for the Mercedes Car Club and it is free of charge.

Is the wire harness adapter the same for all year e55's 2003-2206?

The dealer supposedly changed my pumps but I smell fuel after a fill up so I'm going to pull my back seat and take a look.

For the pumps yes I believe so. For the sender side, yes but it is dependent on the type of sender assembly your car has, there are two different versions. Check if you already have a pump harness installed. They are about 2ft long. If so, someone has definitely been in there.

The work orders describe "RAP Program" and "fuel tank leaks". So I am not sure what they did. It shows work code # 0 47001 04 7

Thanks for this info. I'll have to look into that, because I think I'm going through similar problems. Each time I go WOT, it feels like the pressure drops, it sounds like a rushing sound coming underneath the car, and it happens every time I go WOT, mostly from a stand still. I replaced the fuel/tank system too over a year ago.

Just got my car back from the dealer for the extended warranty fuel tank replacement. I haven't got a chance yet to pull the back seat and check, but the work order clearly lists two "cable harness" - 211-440-05-07 and 211-440-55-08.

Just got mine back from the dealership today WITHOUT the adapter extension installed. New 211-470-00-00 fuel pump installed with the old factory connector. Thanks for bringing this to light; I never would have known.

Yep, they still run and appear to drive fine but one pump spins backwards and the engine runs lean. Definitely not good with your mods. Check your fuel pressure under WOT.

Interesting , thanks for the insight. Had the tank done on my 05 at the end of last year - going to check this tomorrow as well as the repair order .

Amperage with one pump reversed polarity:
https://cimg6.ibsrv.net/gimg/www.mbw...36d681eadd.jpg


Amperage with both pumps correct polarity:
https://cimg7.ibsrv.net/gimg/www.mbw...b3a135aa0e.jpg

I need to bring mine in, dealer says bring it down. It will be interesting to see what Doug finds. It's hard to believe dealers can screw this up. This isn't a difficult job..

Thanks bbirdwell for the thread and heads up.

Yeah there is a tech note on the bottom of my fuel tank workorder . Tech states - also replaced wire harness' with 211 540 07 00 and 211 440 05 07 . Also the pump billed on mine was 211-470-03-00 is that the revised pump ?

How do you pull the rear seat on the car?

Two small metal clips to push at the front under the seat. Easy once you feel around for them. Then just lifts out.

Thanks!

https://cimg9.ibsrv.net/gimg/www.mbw...c56f892ab8.jpg

Can you tell if this is the right connector?

As far as I know there is only one version which you have.

You have the adapter cable installed. It's the one wrapped around your fuel pump lid. You can confirm the wires on pins 1 and 3 of the end of the adapter cable attached to the OEM harness (the one outside the cover) are swapped to pins 2 and 3 on the connector attached to the fuel pumps. It's easier to install the adapter cable rather than swapping the pins in the connector.

:y Thanks.

Fuel pump harness #2
 

https://cimg8.ibsrv.net/gimg/www.mbw...6a3a3597e1.jpg
I did this job myself after my original pumps died at 99k miles.. Really not too bad of a job so far, however there is another harness required which I cannot seem to find a diagram for.. On the parts list it's the 211-440-55-08 "Cable Harness"..

Does anyone happen to have install instructions/wiring diagram/connector pin diagram for this second harness? The car starts/drives without it, but the dealer said its required.. They're also quoting me $1,200 JUST to perform the conversion on this harness- and that's not including hours for any other work like seat/trunk panel removal, etc. as that stuff is already out.

As you can see, I sourced parts for less than half of dealer pricing (at least, compared to my local dealers).

Fuel pump harness #2
 

Just to share a little more-

Here are photos of the driver's side pump as it sits:

https://cimg7.ibsrv.net/gimg/www.mbw...10a3414a5a.jpg
As you see here, the existing 5 pot female connector at the bottom left plugged directly into the port on the new driver side pump- however the connector on the pump at the top of the pic does not match the harness on the car. Would anyone mind snapping a pic of their pumps like this to show what the dealer has done here?
https://cimg1.ibsrv.net/gimg/www.mbw...dadddabec8.jpg
Here's the body harness connestor that was previously connected to the original pump- not even close to matching the new pump..
https://cimg4.ibsrv.net/gimg/www.mbw...f426c68d7c.jpg
Top side of same connector showing wire colors..

Fuel pump harness #2
 

Here are pics of the new harness for which I'm hoping to find instructions for installation/ conversion-

https://cimg8.ibsrv.net/gimg/www.mbw...f60ea8878c.jpg
Here's the complete "#2 harness"
https://cimg8.ibsrv.net/gimg/www.mbw...3cd8c81ab8.jpg
New fuel pump relay with extra wires
https://cimg9.ibsrv.net/gimg/www.mbw...f402ccca24.jpg
Small, very long, and pre-crimped with a square male pin.
https://cimg2.ibsrv.net/gimg/www.mbw...2365d63303.jpg
This connector wasn't in the initial parts breakdown, but dealer I'd need it.. ? Looks like the same 5pin connector that was on the existing chassis harness..
https://cimg4.ibsrv.net/gimg/www.mbw...8124b3b7f6.jpg
Package label from this harness bag, as received.
https://cimg2.ibsrv.net/gimg/www.mbw...df758cad5d.jpg
New fuel pump relay
https://cimg6.ibsrv.net/gimg/www.mbw...edd4badcf7.jpg

Fuel pump harness #2
 

I will absolutely look into this- however, what to do about the missing harness connector for the plug on top of the drivers side pump? Is this the fuel level sending unit? If so, you would think I could just change that connector to the new pump style and be on my way.. right?

Driver's side is not a pump. It is a fuel filter/pressure regulator combination. Yes, one can argue it has a venturi "pump" (non-energized and works by pressure differential) to route fuel back to the passenger side but the actual powered fuel pumps are located on the passenger side.
The parts list item 55 above shows:
Replaced by: A 211-470-64-94 (+001 A 211-440-05-07). The +001 indicates one each. This is the adapter harness that will connect the stock harness to the updated tank inner module. The connector that is plugged in in your photos is for the fuel level floats located on each side of the tank.
You are looking for one of these:
https://cimg2.ibsrv.net/gimg/www.mbw...fd4abfcd6a.jpg

Awesome
 

Thanks for the info and clarification on the driver side..!

This is awesome and surprising as the dealer mentioned nothing of this part #..

So as I have everything, I should be good to go with both adapter harnesses?

Is there any kind of reflash/Star programming needed after everything is installed?

You're welcome. I was pulling my hair out while learning about the intricacies on this car.
The parts person should have looked up and confirmed the parts required.
With the two harnesses (fuel filter/regulator and the fuel pumps) you will be good to go. I suggest that you just upgrade the stock fuel pump relay with a larger version rather than installing the new harness you have in the photos above. To install, you'll have to tear into the stock harness in the trunk to remove the old and route the new; you'd still have the same weakness with the stock size relay tending to overheat and melt. One of the weaker areas on the 2003 to 2005 model years. In 2006 they went with dual relay design to power the fuel pumps.
No programming required after install.

We got our tank and pumps replaced in 2015 on our 2004 E55 AMG and about a month ago the pump failed, the fuse burned through and the relay got hot and burned the relay holder.

I haven’t checked yet but does that mean MB screwed up and didn’t replace the passenger side harness for the relay and didn’t put the short adapter harness in?

If that is the case I will go back and request a check for the pump assembly that we had to replace as well as for the the relay and relay holder. They also need to give us the adapter and new harness then. I’ll put that in myself so I know it’s done right.

Your input is much appreciated.

Thanks.

Not necessarily...it is possible the fuel filter is getting clogged with debris or the fuel pump pre-filters are partially clogged with debris. This would cause an overcurrent condition that exceeds the margin of safety of the original harness and relay (and that isn't much margin) and causes a meltdown.

Replacement of the relay/fuse and harness located in the trunk is not included in the fuel tank exchange. Having said that, the technician should have installed the short adapter harness on each side under the access ports under the rear seat. Doesn't take more than 10 minutes to pull the seat and open the access port on the passenger side. If the pumps have 00-00 on the lid, there better be the adapter harness connected (if done at the dealer; some people have just re-pinned the harness but that raises issues down the road with a future owner or dealership who do not realize the wiring harness is modified). Be sure to pull the connector and see if the plastic around the pins is melted also.

I concur with your proposed course of action; if improper workmanship resulted in the failure and damage, the dealer should stand by their work and repair it for you.

Let us know what you find.

They replaced the pumps in 2015 with the 00 00 pumps and when I broke down on the way to work 4 weeks ago I removed the seat cushion immediately to check if I hear the pumps. I didn’t hear the pumps and I went straight to the trunk. I checked the fuse and the fuse was burned. I then put a new fuse in and the car started and ran for about 20 seconds before the fuse burned again. Then I removed the right side trunk panel and saw the browned relay holder. We got the pumps (again it’s the ... 00 00),the relay holder and relay replaced for $800. I didn’t have time to replace the pumps myself so we towed the car to my friend’s shop to get the pumps replaced hence the higher amount (compared to just $360 for the pumps).

Yesterday after I found this thread (thank you for your detailed work here), I removed the seat cushion again and opened both lids again and no adapter harnesses are there. I then pulled the invoice from 2015 and voila neither
A 211 540 07 00 (adapter harness) nor
A 211 440 55 08 (harness) nor
A 002 542 72 19 (new relay) nor
A 211 440 05 07 (adapter harness)
are listed on the invoice of the warranty repair.

We have an appointment this Friday. I’ll confront them with the “evidence” we have including the fact that at least one E55 burned up because of that.

The bad pumps’ filters are spotless clean. Our tank has no debris in. We verified that 4 weeks ago. Tech removed the entire fuel before he replaced the pumps. I was there because I had the same thoughts as you had about dirt in the tank that this might have clogged up the filters or the pump. I have the pump assembly in the garage and can upload some pictures. There you can see that two of the 4 pins are also brown from the excessive current draw just like on the relay holder itself.

One thing that may be obvious [but then again might not be, depending on the mechanic/person of interest] when replacing a gas tank and really any electric pump - it's purely bad practice to allow the pumps to run dry for ANY amount of time over what's required to prime the pump upon first install. I've seen and heard of individuals replacing pumps and gas tanks but allowing the pump to run inadvertently by leaving the relay plugged in with the battery connected- with little to no fuel in the tank. I've always replaced pumps with no fuel pump relay installed and battery disconnected. Then when install is complete- fill tank at least 1/4 full to ensure complete pump/system priming volume, then plug in relay, followed by battery. i've never had a pump fail using this methodology, and not to call-out a mechanic for bad practice, but with new pumps, it's possible they ran dry too long, which caused eventual overheating, followed by relay failure.

Just thoughts, and as always - research> compile info/data> analyze> hypothesize> then formulate your own opinion (or conduct your own experiment)

I don’t know what they did and how they did it but it’s quiet concerning what I have discovered so far. But you’re correct about the dry run. Especially with these pumps. They get cooled down by the flow-through of the fuel.

It’s not their first hiccup on this car and MBUSA was involved in 6 other repairs where they had damaged stuff on the car while it was there and of course it was never their fault. Once this is through we’re done with them. We do 95% of all the work on our cars ourselves anyways and only go there if it’s unavoidable.

No prime no start situation occurred today. Fuel tank was replaced on 02.19.19 at 104,692 and the car now has 104,849 miles. I started the vehicle this morning & drove directly to the gas station. I filled up & then fuel pumps did not prime-crank no start.
The dealership did not install the fuel system with the adapter harness; but I did install it myself. No visible damage to any of the wires underneath the fuel pump lid. Also has a Flösser 2270 relay for the fuel pumps & the CPS was replaced less than 100 miles ago. Brand new Bosch AGM battery too. After cycling the keys a ton of times, the fuel primed & the 55 did start up eventually. Time to call the dealership again?


https://cimg3.ibsrv.net/gimg/www.mbw...c7f0d76357.jpg

Another Escondido fail :( Our car is there too for a week now. No call no nothing about the status. Worthless grease moneys, worthless service advisors. We should team up against them.

Talked to MB a few minutes ago and they told me MBUSA is fully aware of this mess and dealerships nationwide get complaints about this from customers who’s pumps fail after the warranty replacement was done and MBUSA is supposedly investigating into the problem.

It remains a mystery to me that if they knew from the get go that Pierburg swapped Pins and therefore an adapter harness is needed why this wasn’t added to the Star Bulletin. Furthermore, even in EPC it clearly states for the harness on position 600 this is required of a two pump assembly is used why this isn’t added to the Star Bulletin. Obviously all 211 E55 have a dual pump assembly.

One of their rather disturbing comments was that it seems an awful lot of work to replace the longer harness through the entire car. Well, pay me what MBUSA would pay you to do the work and I’ll do it myself. At least I know then it’s done right. Horrible attitude how they deal with us unimportant customers.

After some 8 weeks the car is back and here are the pictures.


https://cimg9.ibsrv.net/gimg/www.mbw...29831a99f.jpeg
Dual relay wiring harness. Runs from the trunk to the SAM Driver.

https://cimg5.ibsrv.net/gimg/www.mbw...c8354275f.jpeg
Adapter harness to change polarity of the second pump.

Holy s*** what a pain. 8 weeks...I'm just glad to see it's back in your hands.

8 weeks to wait for a decision from MBUSA and 12 hours of labor according to the SA. We’re glad too trust me. After 6 weeks we wanted to get it back and put the harness in ourselves.

Going to check mine tonight for this.

Is there a reason to use the adapter as opposed to rearranging wires on the original harness?

Depending on your model year there is more than just the adapter that you need.

Extreme ease of use.

Confirmed I have this issue, and have had it for a few years. I hope the motor isn't damaged now, given my idle issues. I'm trying to swap the 2 wires now.

Before you do that, have you checked the part numbers of your pump assembly? Did you get a new tank and pumps through the extended warranty?

Yes I confirmed the part number. It was done through the extended recall. I thought the sender was making an odd noise a while back and emailed the SA about it, he told me warranty on the work was a year and I was past it.

I swapped the wires. Seems to run the same, which is not well. I was going to hook up a fuel pressure guage but the one I've got wont fit. Leakdown test tomorrow as the engine is too hot now.

I just saw you have an 03. You need the updated harness from the trunk to the SAM Driver as well or you risk a fire that will turn your car into a crispy critter. Has happened numerous times in recent years since the updated pumps were installed. We forced MB to do that after our trunk almost caught on fire. They were not happy with our overwhelming evidence and documentation we brought to them. They took 9 weeks to figure it out with MBUSA (MBUSA is completely aware if the problem they have caused). MB told us the bill was over $2400 which they swallowed and told us they try to get reimbursed by MBUSA.

Wow, what a mess. I'm worried that my motor is damaged after running with incorrect wiring for so long. Ordered a borescope, and going to do a leakdown test.

If you don't mind sending me any documentation you've got from that process, I'd appreciate it. Does it run from the SAM to the relays on the right side of the trunk? I think I saw that further up the thread.

Correct. Thicker wires and 2 relays. One per pump. The new pumps draw almost twice as much power than the old ones hence the thicker wires to overcome the resistance. As of 05/2005 MB switched to that harness because they knew back then already there are issues with the wires.

Uh oh. Is this the case on my 04 as well? Oh, from the next post, yes, it is.

Is there a writeup somewhere with part numbers for that? I thought all I needed was the "adapter harness" not new wiring in the trunk...just sort of mentally planning for this job which I'm sure I will do at some point.

Mackhack, good to hear you finally have your car back and running. Be advised I released a revised schematic for the '03 to '05 E55. Trigger for the relay comes from N3/10 ME, not N10/2 Rear SAM. Power for the solenoid comes from N10/1 Front SAM and not N10/2 Rear SAM. I was obviously dyslexic when creating the schematic from memory. If you know for sure how your new harness was spliced into the system that would be good information. (Side note: I'll be sending you a PM about programming a replacement Instrument Cluster for my W210 E55. I continue to get CANBUS errors from it whenever the temps are below room temperature so I intend to replace it. Obviously I'll need the mileage on the replacement corrected to match my car.)
https://mbworld.org/forums/w211-amg/...ml#post8120332

If anyone can provide me a VIN from a 2006 E55 (any VIN so long as it is a 2006), I will create and release another schematic that is strictly for the 2006; that model uses an additional pin on the ME to trigger the other relay. Easier to figure out the connections if I only have to look at one schematic rather than four partial schematics (the E55 has four different harness configurations for the fuel pump relay and pumps). Two iterations in the '03, third iteration in the '05, fourth iteration in the '06.

We had it done last year in May. So it’s been a while.

I can try to find out what they did in the front. I have currently removed the dash board, both front seats, rear seat, everything out of the trunk, and the middle console for a major project. So right now everything is pretty accessible :) During the gutting I have noticed that the dealership didn’t do a “The Best or Nothing) Job at all. The relay holder in the back where mounted where they shouldn’t have been mounted, they forgot a dirty oily rag behind the right side trunk panel, ruined the right side trunk panel (punched a hole in it), stained the rear carpet, put the carpet over the plastic panel covering the right rear fender between the door and the rear seat cushion, used zip ties instead of the corresponding nuts and bolts per EPC and a few other things. I fixed everything myself as I know they will simply deny any wrong doing as always. I didn’t even want them to put the harness in and asked them if they would simply give me all the parts and I would have done myself and I would have known it would be done right.

I have to add a new cable harness to my SAM Driver in the next few days anyways and have to take it out for that retrofit. I’ll report back if I see what they did.

About your cluster, no problem just PM or email me for details.

Sounds like the stuff I had to remove for the dynamic seat retrofit.

What's the best way to go about getting upgraded wires and relays? Just buy them, or try to bug MBUSA about it?

I am replacing the factory multi contour seat air hoses and replace them with the thicker drive dynamic seat air hoses, take out all old harnesses from my various retrofits that I have done over the years, put in my custom made Neck Pro cable harness that I just finished assembling, add the NTG2.5 cable harness, replace the COMAND frame in the dash to hold the NTG2.5 properly in place, remove all obsolete NTG1 control units, change the pins of the Tele Aid control module so the latest one will work also in my car.

I also have disassembled both drive dynamic seats to replace all air cushions as most of them are leaky after 15 years and the cushions are discontinued. Daimler sells what’s left at hand and won’t make more in the future. Once that is done I will also do a few cosmetic things in the engine bay. I just replaced the oil filler neck, valve cover seals (all 4) and oil filter housing seals along with a brand new cowl (California sun completely destroyed the rubber lips). It’s rather a long term project at this time. LOL

Back to topic. After we had the relay issue I dug into bbirdwell’s info’s here and did my own research between WIS, EPC, pictures, videos and articles of burned to the ground E55s and other Infos that I found to strengthen my case and compiled it to a folder of about 30 pages. With that in hand we went back to MB and confronted them with the evidence. We had a 2 hour meeting with the service advisor manager. The most daunting thing is that I also involved high level engineers and managers at MB in Stuttgart about the issue and slowly but surely it was clear to us that MB was fully aware of the issues and calculated that it’s cheaper to have a few cars burn up than through more parts in for free than necessary.

What that means is this: If you’d go to the parts counter and order the new upgraded pump you’d get all the add-on parts like the updated harness, adapters and so on) that are listed under the pump no questions asked. But going through the extended warranty they only replace the bare minimum. And that is where the problems start. Most customers are clueless anyways and would never even know that MB doesn’t do it right. I can’t eben blame the mechanics as they only follow instructions (TIPS and DTB). But 8m sure the smarter mechanics amongst the herd figured it out that there must be a discrepancy between the right way of doing it and the MBUSA way of doing it.

I know that we have made MBUSA as well as the mothership fully aware of the issue or better that we as the customer know they ****ed up. I’m glad that I have the connections that I have to MB in Germany and that I made MB to fess up and swallow the cost of doing it right.

Ihope this gives you a rough plan of how to tackle your dealership. In my opinion, you shouldn’t fork up a dime of your own money to get this done. Either make them do it or at least make them hand over all parts needed and do it yourself. Like I said before, I wish I would have done the work myself after what I found after the fact.

Superb info, thank you. Yeah I've also been repairing leaky air bladders and a dried-up cowl.

A word of advice while you've got this much apart, take out the HVAC and reinforce the thin plastic stoppers for the flap motors. If you look at it, the white plastic bit spins around and bumps into these plastic end points, to create boundaries. If yours haven't yet, they'll eventually punch through, and then the flap positions will not be where the computer thinks they are.
I did this repair partially with what I could access with the dash off. Planning to do a more thorough job soon to repair the ones I couldn't reach.

Do you habe pictures of that? I have put the dash back in already. Didn’t know of that issue but that is good to know. I do have one flap that I believe gets stuck sometimes. I notice it by a loud noise sometimes. I believe the motor tries to move it and once there is enough tension on it then it suddenly moves like two tectonic plates which cause an earth quake. Sorry can’t explain it better.

I know it exactly, it is a good description. What you're hearing is that the stopper broke, motor keeps pushing on it, and the plastic flap pushes through the rubber lining/gasket that it is supposed to sit snugly against.
1mm more thickness of plastic and these would last forever, but a corner was cut and eventually all of these units will go bad as the plastic ages. Not sure if MB or the manufacturer is to blame.

I'll send photos, I should have some but need to look around, and don't want to thread-jack further, sorry OP.

Send me a PM with your email address and we exchange pictures that way to avoid the hijacking.

I presume this kit is not enough to fully convert my 04 to all the required updates then?

https://www.fcpeuro.com/products/mer...des-2714700000

Nope not even close. FCP Euro is a sucker deal anyways.

Sometimes their prices are quite competitive so it's a no brainer with the warranty. I take it that kit is not a good deal. That said, it means I could get new fuel pumps as much as I want and only pay once....so there's that.

Care to steer me right then?

Their warranty counts on people who don’t keep their car until that part is worn down our out and send it back for a free replacement. Americans in general(!!!, not all of course, just to avoid the stereotype) don’t keep any car for long (or long enough that the part would wear or break) and therefore the warranty is void as soon as the car has a new owner. FCP is/was never cheaper than dealerships that sell online.

That being said, why would anyone buy more expensive parts from FCP Euro when the car is never long enough in ones possession to take advantage of their life time warranty?

Another issue I have with them (and that is my personal opinion as I care about these things) is the fact that they often label OEM parts as OE or aftermarket parts as OEM parts. An OE part is simply not an OEM part (and that nonsense the part comes off the same assembly line only comes from people who have no idea about what a manufacturer tells their suppliers about the product, I could write a white paper on that) and anyone who doesn’t get it or doesn’t care opens up issues just to save a few pennies. If the budget is that tight a Ford might be the better brand for these people then. I have no issues with saving money but saving money with the wrong parts is a problem.

Lets get back on the topic.

This might be of interest for some here who truly care about this mess:
In the 211 and 219 class platform up to code 806 both fuel pumps are getting actuated via one single relay (as we all know by now). One of the two fuel pumps is only there to pre-fill the fuel feeder bowl.

The reason for the change explained:
As of code 806 (31.5.2005 - 1.6.2006) the second fuel pump is getting actuated by a second relay (also as we all know by now). The ME is programmed to only turn on the second pump if the primary pump's fuel delivery rate is insufficient. This is done to accomplish that the fuel doesn't get heated up unnecessarily through the pump's internal dissipation power.

The updated cable harness is connected to plug 4 pin 36 (36 is the primary pump in the single relay (K27/1) as well as the double relay harness) and pin 27 (secondary fuel pump relay K27/2).

Pump unit sender/filter unit and the two harnesses aren’t enough for early cars?

Is that pin 27 in plug 4 of the motor electronics? Same plug 4 as pin 36?

Yes it is. I will upload some pictures once I have my SAM Driver out. I’m busy today with my other projects and have to prioritize them a bit.

Thanks for the wall of text?

Yes of course the warranty counts on people getting rid of the cars. That doesn't make the warranty a scam. In fact it explains why they can offer it - most people don't invoke it.

Also I have no trouble believing that they sell OEM Mercedes parts. They scratch out the part number due to....licensing? The best argument you could have is that they are like 2nd tier rejected parts that would otherwise get thrown away. I doubt that's the case - I've never heard of anyone getting a "bad/knockoff Mercedes part" from them. That's because that's not what they sell.

Anyway, all that side, you didn't answer my question which was, if that kit was a bad deal (and/or incomplete) where should I be looking instead? It's not at all clear to me what I need to do to my 04 to make it fully happy with the updated pumps without burning my car down....kind of important.

I call it a scam for the reason I explained it. They offer a warranty that they know few will ever use and on top of that the prices are higher than the dealership charges. It’s my opinion about their business model. I see your point and accept that. I don’t like to argue over opinions anyways.

Your 04 if you go with the new style pump requires additional parts (that’s why we discuss this here over and over).

That being said, go ahead and buy the kit from them then go and buy the additional parts that would be sold to you at the dealership’s parts counter like the harness I keep talking about, the adapters for both sides, small parts, etc. pp.

I hope that clarifies it. If not let me know.

Out of curiosity do you know how the ECU determines when the primary pump's delivery rate is insufficient? Were other components added for code 806 to make that possible?

I'd speculate that it goes by load %

RPM sensor on the output side is used to determine the need for it. The E55 uses the gasoline to cool down the pistons and inner walls of the cylinders, therefore it’s important to have a) enough gas coming in and b) as cool as possible. A side effect of cooler gasoline is that it burns cleaner and has more Corbin molecules which is the actual “fuel” that burns. The engine gets really rich the faster the engine goes, that’s why the back is always dirty with soot.

2006 E55
 

good day all
I have 2006 E55 And now it’s been almost 5 years since I bought it and recently I have been smelling fule inside and outside the car.
I did not replace the fule tank like most of you did because I have had my tank checked and they said it’s not from the tank. So it seems like the 2006 is different from the other failures or maybe they did not check my tank properly.
here is my vin number if you are still looking for a 2006 vin number:WDB2110761A625976
and I hope you guys recommend me with any possible checks that I can do because I’m from Saudi Arabia and I don’t think that the warranty is valid here to replace the tank if the problem is from there. Thanks in advance

Look into the fuel rail damper (or dampener). There are threads on it. If the smell seems to be coming from the engine bay (vice the rear of the car) this is probably your culprit. Cheap and easy, so, for your sake, I hope that's it.

Either they saw the fuel or they didn’t. My recommendation. Fill it up until it’s full. Remove the rear bench and take the service lids off and check for yourself. That’s it.

The extended warranty is a USA thing and your car would not fall under that.

E55
 

thanks man I will definitely check this one out.

E55
 

okay man thanks for the advice I appreciate it. 🙏🏼

2006 Tank Warranty just done
 

been reading a lot of your replies on this thread and the Star Diag thread! Thanks for all your info.

My 2006 E55 jus the had this work done. I’m going out there today to check for all adapter harnesses etc.... and since it’s a 2006 it will be dual relay and should solve most of the crispy critter issues. Just confirming that the 2006 also requires an adapter harness on the passenger side? And any thing else I should look for thanks again!

If new pumps with part number ending in 47 00 were installed a harness is mandatory or one pump will pump forward the other pump will pump in reverse due to changed polarity pins in the pump assembly.

https://cimg4.ibsrv.net/gimg/www.mbw...ab67b4127.jpeg
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looks like they did everything correctly to me! Thanks again. Glad I checked it, and thanks for all the foot work on this.

The tank is often not the issue. Mine was a leak through the electrical connector port of the top hat. A new one of those and a seal and no more leaking. I reused my old pumps, added the electrical adapter as the new top hat was the new style and tested fuel pressure. If only they sold the top hat separately. I got lucky and scored one from someone who's mechanic didn't use the adapter and the pumps failed.

I also believe it’s never the tank but the tank is part of the extended warranty deal when you get everything replaced by MB for free.

+1 Absolutely, I would take the whole tank if offered. I guess it's just an interesting observation that outside of the US and\or warranty, I can't imagine anyone would buy a new tank. And they don't seem to have issues. I can understand that MB decided it would be easier to replace the whole thing pre assembled.

The difference is the type of material used to make the fuel tank parts for US spec vs. Rest of World spec.

That material reacts differently to our gasoline.

The US has the ULEV/VULEV vs. LEV in the rest of the world. It’s funny that the government acts like it cares about the environment so much when we are one of the worst polluters in the world. The US military is actually the worst polluter, not China, Russia or India as they like to portray it in the mainstream media.

Hi Everyone,
I can’t say that I’ve made too many posts here but I want thank you all for the information you provide to keep these awesome cars on the road. I bought my 03 E55 in Feb of ‘19 with 38k miles on the clock and it’s been great so far. Original owner bought it for his wife on her 50th bday 🤯. So far I’ve only added lth and thought I’d be happy there but I’m thinking a pulley might be in order lol. Anyway, my car wouldn’t start the other day and after replacing the cam and crank sensors I thought to check the fuel pressure and nothing. The pump primed but no pressure. I just finished replacing them tonight and the car started right up and seems to be running fine. My old pumps did get a little hot at the pin connections but the wires aren’t melted in the slightest. I suppose that doesn’t meant that they aren’t damaged and a resistance test would prob be best just to be sure. While poking around the forum I came across the threads with the relay issue and thought I’d take a look at mine just to be sure it wasn’t melting down, and sure enough it’s fine. I see that MB now has an updated dual relay harness, is it necessary or is the 70A relay sufficient? I want to make sure it’s done right but if the extra relay isn’t necessary then I don’t want to go through the hassle. If it is necessary, where can I find the part number and a possible write up on adding the new harness?
Thanks, Collin

Collin, it’s 100% necessary. That’s why I stress it so much for pre 5/2005 E55.

Just stopped in to my local stealership and they had no idea what I was taking about and nothing in their system for an updated relay harness. Would you happen to have the part number or know where I can locate the harness?

Tell them to learn how to use filters in EPC if they wanna sell parts and make money.

Dealerships are so aggravating. If they sell you the pump with the last part number, it automatically shows the new harness and all other parts that are needed.

Only if they go by the MBUSA warranty bulletin they don’t use the parts because MBUSA wants to save as much money as they can and that leads to E55s that burn to the ground as I have seen now numerous times. I collect all the stories, articles, pictures and videos of US E55s that burned because of the irresponsibility of MBUSA.

I don’t share Mercedes copyright material on forums anymore. You can send me a PM with email address and I look it up and send you the information.

Want to say thanks for all of the great information here, got my 04 back on the road when the oem fuel pump relay burnt up a few months ago. Am experiencing new issues now and think it may be related to the pumps or filters. I have been chasing a fuel pressure fluctuation around 2k rpm where it rapidly bounces between 70-85 (where normal idle is 78) . I replaced the fuel damper which seemed to (perhaps coincidentally) eliminate fluctuation for about a week but since has returned. I've continued to drive the car, in manual mode on hwy when needed to keep the RPM above 2k when needed as once it's out of the 1600-2k rpm "danger zone" the fuel pressure immediately returns to normal readings.

Yesterday I noticed when I started the car the fuel pressure very slowly built up to 65, once I began driving it resumed normal behavior, but after shutting down a few hours later the pumps were completely dead, - until I reseated the relay. Now the pumps energize but still only slowly (over a few seconds) build pressure up into the 60's , before it would immediately shoot up to the 78 - could this possibly indicate one of the two pumps has failed? I've inspected all of the pump and relay wiring, all wires have continuity and nothing is burnt on pump or 70A relay harness that I put in. All of the updated pumps and harnesses seem correct, these were replaced under warranty by previous owner a few years ago. The symptoms persist when I bypass the trunk relay and put power directly to the pump assembly, so I think I can rule the harness out of the equation.

I guess my question is two fold- one regarding the fuel pressure fluctuations and the other regarding the recent lower pressure. Is there any way to test the regulator that is located in the driver side pump assembly? Is this an internal mechanical regulator or something electric like that module on top of the assembly?

As for the pumps, I think I need to pull the top hat off and verify wiring condition under the hat, if no visible issues build some kind of inline ammeter as bbirdwell has done to verify the pump draw. This would show if one of the pumps is not functioning, I assume there is a possibility of the fuel filter being clogged, but would think this to manifest itself as a gradual drop in pressure and/or overworking of the pumps resulting in burnt wiring. Perhaps try pulling the pump apart to replace the filter as described in other threads

Not sure if the low pressure could be indicative of a pump failing because as discussed earlier the older model years with 2 FP relays only use one pump until the demand requires energizing the second - if true I'd assume one pump is all that's needed to run the car indefinitely under low load operation

Banging my head against the wall with this fuel system.. starting to think about pulling everything factory out and running a complete aftermarket system with all new wiring


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Yes you can run the car with one pump even at WOT (until something goes horribly wrong of course). I had my second pump running in reverse until I ran out of gas because of a wonky sender and also found that the adapter harness was missing.

There is no regulator in the pump assembly to my best knowledge. If you don’t have the newer harness in I suspect that is your problem. Especially without the adapter. Without it one pump delivers fuel to the rail the other pump pumps in reverse.

What’s the difference between the MY05 revision of the harness and the earlier 03 and 04s?

Some dealership forgot to use the pump adapter harness when replacing the tank in my 04/05 (lol) build and the relay area probably started melting from the new pumps way before I got it regardless.

I did the 70A upgrade and added the adapter harness + made a foam insert for the original harness going into the RH side pump cover. Still at risk for issues or should it be enough?

Please read the thread. I have personally explained it numerous times and I’m tired of writing and explaining it over and over again every week because nobody wants to read anymore.

I’ve read this thread like 20 times.

Someone mentioned there are four total revisions ending in the dual relay setup. I want to know what random little things they changed out for revision #3. I get that the harness from one of the SAMs to the trunk is mandatory everywhere but here where they were forced to do the extended warranty and will pinch every penny possible performing it.

I didn’t find anything like that or what I feel like I can share publicly from some deep down documents not available to the public. Maybe a connector changed or the thickness of a cable or the length of a cable changed. All these things constitute in a part number change.

The change to the dual relay, dual fuse setup makes perfect sense though as it helps to keep the current consumption per power feed down as well as the fuel heat since only one pump runs and the second one gets activated only under conditions like WOT and only if needed. I really don’t feel like going much more into details as I don’t like to post stuff that’s not for the public.

In the end it’s up to each owner to either fight to get the repair done right or risk that the vehicle burns up like many before after the warranty repairs.

Coupesedan,
I was considering trying to swap to the updated two relay harness on my E55 but that doesn’t seem to be possible as I wasn’t able to get ahold of the parts info. I’m thinking it will prob be easier just to run a separate power circuit direct from the battery that’s triggered by the old relay.

Of course it is. The harness is no secret menu item just because the dealership won’t help ya.

I just haven’t had time to send you the list of all the parts. Be patient, please.

No worries mackhack. Just seemed like from your recent post I would have to find an alternative solution and I wasn’t trying to be a pain.

Please relook at the revised schematic. Relay solenoid is powered by the front SAM and triggered by the Motor Electronics, not the rear SAM; I misread the schematics on my laptop many months ago but have since corrected it. My bad for the earlier erroneous information. See here:
https://mbworld.org/forums/w211-amg/...ml#post8120332

Rev 1 (early model year 2003): fuel pump relay in trunk with integrated fuse. Air pump relay under hood over auxiliary battery. Fuel relay single triggered by ME.
Rev 2 (late model year 2003 and model year 2004): fuel pump relay in trunk with separate fuse. Air pump relay under hood over auxiliary battery. Fuel relay single triggered by ME.
Rev 3 (Model year 2005): fuel pump relay and air pump relay in trunk with separate fuses. Fuel relay single triggered by ME.
Rev 4 (Model year 2006): two fuel pump relays in trunk plus air pump relay in trunk with separate fuses. Fuel relays each triggered on separate pins of ME.

FWIW, in model year 2007 the E63 version of the W211 went to two each fuel pump controllers that vary fuel pressure based upon a Pulse-Width Modulated signal from the Motor Electronics.

Are fuel pumps replaced during gas tank recall problem?
 

In 2019 I had my fuel tank replaced in my '05 E55 under warranty due to the smell inside the car. Within a year my fuel pump failed and Mercedes charged me $3000 to replace pump and harness. My question is, when they do major work like this, how come they don't install new pumps, but instead put the old ones back into the new tank? Well guess what, my pump just failed yet again and it's past the 2 year warranty. Have to come up with another $3000! What the hell. Why in the world would they put the old pumps back in I will never know. Would love to get reimbursed somehow for this BS! Would love to hear replies about this. Thanks guys.

I was under the impression that they were supposed to replace the entire tank with everything in it.

That's what I thought until the service agent said pump not included to be replaced. So when my pump failed again the other day the steelership wouldnt give me the time of day. They brushed me off saying latest pump failure is out of the 2 year warranty period. But i want some money back if the pump was included when the tank was replaced and it failed within a year. Hopefully i csn get some real answers on what parts are all included in the gas tank replacement. Ugh!

I've been going nuts trying to find out what parts are in the the fuel tank system. The part number is 211-470-03-00, which has been discontinued everywhere I go online. So there has to be the info I need to prove that part was replaced. They consistantly tell me that the pump wasnt replace. Am i to believe that they will replace the entire fuel tank system, and put the old pump back in? Im no idiot. The Paramus service depart in NJ appear to be clueless, and it really pisses me off. I'll go there in person tomorrow and talk to the parts person and get the list of parts in that system. I hate dealing with morons.

I am pretty sure all of the original parts were superceded and none of them are forwards or backwards compatible meaning you generally have to replace everything in one go. My guess is you had to have new pumps as is supposed to happen.

I was lucky enough to be able to source a good top hat so that I could retain all the old stuff but I still needed the adapter harness for it.

Good luck on the dealership. Personally, I would not expect much since it is an older car and it's getting harder to source parts for it. Try calling FCP Euro and see what they can do to source you a fuel pump and the filter/regulator that matches. It will run you about $1,000 for the parts and you can do the work yourself in a couple of hours.
Don't forget to check the relay and all connections.
EDIT: are you sure it's the fuel pump and not the relay? First thing I would check for a fuel pump failure is the fuel pump relay or the connector that attaches to the fuel pump top hat.