W211 E55 fuel tank replacement. Verify parts!
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).
Here are photos of the driver's side pump as it sits:
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?
Here's the body harness connestor that was previously connected to the original pump- not even close to matching the new pump..
Top side of same connector showing wire colors..
Here's the complete "#2 harness"
New fuel pump relay with extra wires
Small, very long, and pre-crimped with a square male pin.
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..
Package label from this harness bag, as received.
New fuel pump relay




Last edited by bbirdwell; Mar 30, 2019 at 10:18 PM.




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:
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:
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?




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?
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.
The Best of Mercedes & AMG
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.
Last edited by Mackhack; May 7, 2019 at 09:20 PM.




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.
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.
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.
Last edited by Mackhack; May 8, 2019 at 10:28 AM.
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.
Just thoughts, and as always - research> compile info/data> analyze> hypothesize> then formulate your own opinion (or conduct your own experiment)
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.
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?
Last edited by eFifty5AMG; May 17, 2019 at 12:20 PM.
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?
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.
Last edited by Mackhack; May 17, 2019 at 12:45 PM.
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.
Last edited by Mackhack; May 17, 2019 at 07:33 PM.
Dual relay wiring harness. Runs from the trunk to the SAM Driver.
Adapter harness to change polarity of the second pump.
Last edited by Mackhack; Jul 28, 2019 at 01:35 PM.








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.


