dcsimmons

I have a 2006 MBZ E-350, and about 6 months ago I started getting a warning after 5 minutes of driving or so that would say "Visit Workshop". I noticed the air pump was running longer than usual, and figured a timer had been triggered by the computer displaying the warning. So I bought a new pump and figured I'd replace it when the time came assuming the cold winter would challenge the pump with the more dense air, as it did. It is now deader than a door nail.

There has always been a small air leak in the rear, but it would go unnoticed unless the car sat for a week or so. I know they all have a problem, it is fixable, but for me it wasn't worth fixing. Last week the rear of the car was a little lower each day, I never heard the pump come on anymore, and on day 6 it was low enough driving the car would be a problem. So I replaced the pump.

After replacing it, I expected the car to raise automatically when the door was opened, the car was started, or ultimately using the "raise car" button, but the pump didn't come on. So I looked for the 40 amp fuse in the fuse box in the engine compartment (see attachment), and it was fine. I replaced the relay (Part # 002 542 76 19), slot S in the same fuse box, and still nothing.

I know the pump is good, because I run it manually by hot wiring it to get the chassis to raise up. . And while there is always a possibility of a wiring issue, I have double checked continuity at the plug to make sure the connections are good from the pump to at least past the plug that goes to the wiring harness and back to the computer.. This car has always been garaged, and kept clean, even in the engine compartment, and I know the suspension quit working because the old pump went bad, not because of a wiring issue, so I consider it being very unlikely it is a wiring issue.

My questions are:

1.) I have a 2006 MBZ E-350 (W211), and I am pretty confident it is slot "S" where the relay goes, but not 100%. sure because I have heard F74, which I can't find, is the one. I believe it is the location for older W211's like the E-350's. Anyone know for sure?. (See attached diagram),
I believe Slot "S" is the furthest back slot, and actually a little bit lower than the rest in the fuse box, but am not 100% sure. because I can't visibly see it. It is closest to the firewall, and on the most left side. That is the relay I replaced, but is it the correct one?
2.) I assume the 40 Amp fuse is the one labeled in the attached picture. Is that the correct one?
3.) I have been told inconsistently that a computer has to be connected to turn on the air pump on the first time after it is replaced. I doubt that is true, but if it is, then I am sure it is my problem.

Anyone have any ideas for me?

Thanks!

kaane

You need to hook up a scan tool and see if the airmatic has any codes.

dcsimmons

Thanks for the reply.
Before spending the money to scan the codes, I was hoping to verify I have the correct fuse and relay labeled.
I looked at the info below and didn't see any charts or diagrams showing the relay or fuse positions. And the links were dead. Do you have a diagram of the fuse /relay layout?

Again, thanks for the reply!

bbirdwell

See attached for relay and fuse info. This fuse list is not accurate for the E55 AMG model, only non-AMGs.

Since it appears the leak is in a rear air spring, try putting the suspension into Sport 1 or Sport 2 mode. If the leak is in the line leading to the external tank, these two modes close the valve to isolate the air bladder from the external tank. If it is still leaking, you need to replace the rear air springs.

I have not heard of needing Star to perform initial actuation of the compressor. It is possible, but not probable, that the system threw a code and wants it cleared before it will activate (sort of like the transmission codes must be cleared by Star when the fault is electrical). An iCarSoft 980 or equivalent that reads MB codes could be used to clear the codes.

Let us know what works for future reference, please.

dcsimmons

That is exactly what I was looking for, and I have a couple of questions.
I did have the correct relay and fuse, but is this relay (FS) sequenced off of any others?
Also, do you know if the iCarSoft CR Plus Professional does all the things the 980 does? I was looking to purchase it since it looks to handle many more cars, but won't if it doesn't handle the AirMatic suspension.

bbirdwell

I am not aware of it being sequenced but I'll have to look at the electrical schematics to confirm. You could try jumpering the pump power circuit leads to see if that activates the pump. IIRC, those leads are labeled 30 and 87 on the relay. Do a search in the W211 AMG section on fuel pump relay and fuse maintenance and you'll find schematics and what-not describing it.

Ref the CR Plus Professional, I cannot say but it looks pretty good from the website description. I use my 980 for a quick 3-minute check of my car for minor issues (example: fuel cap left loose). The full-up diagnostic system takes up more room and takes five minutes just to set it up and connect everything. If you go with Plus Professional version, be sure to put up a review of it here.

kajtek1

I think the long drive with active leak not only wear out the compressor, but also triggered hard code that now prevents the computer to engage the compressor.
Fact is that MB is very mysterious about the system and we have to learn by experience how it suppose to work, but true is that you will not go anywhere without a scanner.
Can you hear the relay clicking when you start the engine? It might be hard to troubleshoot, but those relays don't have good reliability records.

dcsimmons

Thanks again, I think I will by the CR Plus. Looking at the iCarsoft MBZ II, it actually says something about the airmatic. It doesn't in the description of the CR Plus, but I am guessing just not enough room.
I'll let you know what I come up with.

Thanks again!

dcsimmons

I think the relay actually comes on when the you open the drivers door as well, right? I have been hearing a click and assume it is this relay. But I also have tried using the raise car function, but don't hear anything when I push the button. I am hoping you are right, that it is a computer thing.. I just ordered the scanner and will have it Saturday.

I'll let you know what I come up with.

Thanks!

kajtek1

I never come to direct experience, but reading the manuals posted by konigstiger, I remember that system is design to level the car with open door, using the tank pressure and only when tank pressure drops too low- the compressor is activated.
Those things are impossible to observe by a driver without scanner. or in my case when I had troubles- I install pressure gauge on the line, what helped a lot in my troubles.

dcsimmons

Update!!! I received the iCarsoft CR Plus, and it doesn't handle the Aromatic suspension, so I exchanged it for the iCarsoft MBZ II, and it does handle the suspension and very well it appears I might add. The only error I am getting is error 5508 which says, "The pressure line system leaks".
To verify the scanner will show if the relay and fuse are bad, I pulled both, ran the car, and they both gave appropriate errors after being removed. Put them back, reset the codes, and only the 5508 shows up.

I checked the system for leaks form the pump to the valve block, found a very small one in a line going to the rear, fixed it, and now there are none at least around the valve blockl. And as I mentioned before, I have had a leak in the back for 9 years, and it is small enough it take several days for the rear to start sagging enough to discern the difference. I haven't found anything in forums to suggest if there is a small leak, the system will shut down, and not turn on the pump anymore. And again, the pump is brand new, and I hot-wire it to get the car up enough to drive it while I figure this out. It raises the car very quickly, so I would have a hard time finding it to have a restriction somewhere in a line.

I can clear the 5508 code, and it stays away till the car needs to raise up. I hear the pump come on for not even 5 seconds, then it goes off, and it throws the error.

Any ideas?

kajtek1

Can you observe the pressure with new scanner?
When we don't know the software programs, we have to learn by experience.
My first guess would be that if the computer does not see pressure increase in 5 seconds, it judges it as main leak and shuts whole system down.

dcsimmons

I can't observe it real time. The suspension system will not change state if I am real time observing values, so I have to back out, change something, and then look again. What I did to verify it wasn't a lack of pressure in the system in making it work, was to hot wire it to make sure there was adequate enough pressure in the system, disconnect it from being hot-wired, turn the car on and then try to raise it with the raise button. The display showed it was raising, the pump came on for not even 5 seconds again, the car didn't raise at all, but the interesting thing is I didn't get any errors. I did this a few times and nothing, didn't raise the car, but no errors. So the error 5508 seems to be unrelated to why the car doesn't raise.

Today I am going to approach fixing the leaks in the rear. Hopefully it won't be an arduous task.

Sleeper Benz

I thought you could see the pressure in the system in "real time" as I recall driving with the iCarsoft MB II device plugged in and observing all kinds of "real time" data from various sensors. You need to toggle "live data" or "Real time data" or what ever it's called on there from the same menu as you would "reset" or "view" a code.

If you can't see an air pressure value on there, the pressure sensor or module it is reporting to may have an intermittent issue. example: "Sensor falsely reports max level reached and calls for shut down of compressor before proper pressure level is reached" would be one scenario. This would possibly explain why your compressor shuts off after 5 seconds when it can really run for a few minutes if it is called for.

dcsimmons

Thanks for the reply! At least for me, I can observe air pressure real time, but the suspension system will not change state while monitoring it, and so the ability to see the pump turn on and monitor the pressure doesn't seem to be possible for me at least.. The opportunity is lost in monitoring it as it is initiated after sitting for a while, because opening the door or turning on the key activates the Airmatic system, and the scanner hasn't even had a chance to sync with the system. As I am sure you observed, one nice thing about the scanner is that you don't have to start all over in it booting up if it is still plugged in even if the key has been removed. But it won't get new data until the key is turned back on. And it appears as though going into "Suspension" mode with the scanner shuts the compressor off as if it can only be on when you aren't actively scanning. Your system may be working differently, and if so, then the difference may be why mine isn't working correctly in the first place.

Knowing these systems are continuously leveling the car, I drove around monitoring the air pressure hoping to catch it real time, knowing the pump would have to eventually come on. But I never caught anything happening all the time I was in the "suspension" mode of the scanner. Then immediately after backing out of the "suspension" mode, I did hear the pump come on for a few seconds and I received the "visit workshop' message again, checked for codes, and the 5508 was thrown again. So I assumed, maybe wrongly so, that while you can monitor the air pressure, the pump won't come on while you are doing so, so to watch the pressure rise isn't possible.

Even though my air pump is brand new, and the filter as well, I am leaning towards it being a pump that draws too much current, and so the system shuts if off before blowing a fuse. If the system is intelligent enough to do that, then it makes all the sense in the world. The only problem is I would think the system would throw a code if that was the case as well. I know my leak is very small in the system, and I have no leaks between the pump and the valve block, so my problem actually being the leak may not be the problem at all. It may just be a system not smart enough to tell me it is drawing too much current.

Again, thanks for the reply.

dcsimmons

I meant to add that my pressure sensor moves all over the place, and never appears to max out, but I'll pay more attention to it.