KerryChadderton

Hello All,

I am the new owner of a 2004 E55 AMG that has not been well cared after. I know the PO. He got tired of dumping money into it. It was a daily driver as of last week when it shut itself off whilst warming up in his driveway. It is my problem now but I'm up to the task....I think.

I have checked the Fuel Pumps circuitry. I've got power at the relay. The relay is confirmed good. No wires, nor connectors are burnt in any way. One pump is shot; No continuity. The other is locked up (has continuity, doesn't run with external power supply).

Here is the point of my thread: I have no power at the right side connector on the fuel pump assembly. This connector has 2 thick brown wires and 2 thick blue/red wires. No power in any combination, at any time. Cranking or not. I want to have power there before I order the new pumps.

What am I missing guys? Any ideas?

Additionally the rear airbags are shot and the car is sitting on the fender wells. If this triggers some "fuel shut off" protocol please advise.

Thanks in advance! -Kerry

bbirdwell

https://mbworld.org/forums/w211-amg/...lacements.html

https://mbworld.org/forums/w211-amg/...ng-my-car.html

https://mbworld.org/forums/mercedes-...-circuits.html

https://mbworld.org/forums/w211-amg/...r-pigtail.html

https://mbworld.org/forums/mercedes-...tcs-ideas.html

KerryChadderton

bbirdwell; Thank you for the links. I started this project by reading about your problems and solutions last night. I just read each of the links and went back to testing.

I have only one relay, and no fuses, in front of the airmatic tank on the right rear fenderwell. Previously I was testing the relay at "A" on the rear SAM. It is working.

With the ignition in #2 position the fenderwell relay has power to the + side of the relay trigger but nowhere else. The ground on the trigger seems to not be grounded, or it is switched by another circuit. Neither of the 2 large wires; blue/red & brown/red have + power. The relay itself bench tested okay. I checked every fuse I could find in the trunk, rear SAM & Engine compartment.

I do not have access to WIS or any wiring diagrams unfortunately.

I've been at this since 8-830 this morning. It's 3 now. My head hurts. Is it too early to start drinking?

I appreciate the help this forum has provided. I hope I'm not being a PITA but any insight to where the power comes from would help. -Kerry

bbirdwell

One more.

https://mbworld.org/forums/e-class-w...les-chart.html

My last input at the end discusses what I found ref which relays control what in the AMG and non-AMG.

I do not have an answer about the source of the power for the the relays. The fuel pumps energize when the engine is running. When not running, even with the key on, the pumps are not energized. I learned that when I connected my home-brewed volt/amp meter.

The relays work by an open-collector arrangement; i.e. the ground wire at the relay is not connected to ground until the computer "pulls" it to ground.

Also, be advised you will most likely have to clear many "stored fault" and "event" codes when you finish.

evilpenif

Did you ever find the fuse for the fuel pumps in a 2004 E55? I also have just 1 relay on the right hand side with no fuse next to it and all the paperwork list fuse 4 as a 20amp fuel pump fuse but thats in fact a 7.5amp IC pump fuse.