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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 milegage 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.
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.
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.
okay man thanks for the advice I appreciate 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.
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!
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.
Last edited by Mackhack; 09-20-2020 at 06:52 PM.
Reason: Fixed some typos
If new pumps with part number ending in 47 00 were installed a harness is mandatory or on pump will pump forward the other pump will pump on reverse due to changes polarity Pins in the pump assembly.
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.
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.
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.
+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.
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.
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
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?
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
Last edited by corvettekyle; 10-07-2020 at 12:01 PM.
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?
Last edited by coupesedan; 10-07-2020 at 02:38 PM.
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.
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.
Last edited by coupesedan; 10-07-2020 at 03:34 PM.
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.
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.
09-17-2020, 02:46 PM
