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2002 S430 AMG wannabe
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Discussion Starter #1
Hi Guys!

I am spending all my free time to read EVERYTHING in the ecyclopedia section, and I am not finding a solution to my problems. And I have two.

The first is "Airmatic - Car too low" warning that crops up here and there. Few observations.......it happens ONLY in the #2 sport setting, and not in #1, or in "normal" (I don't like "normal" at all! The car feels big, sluggish, and too soft). If I have it in #2, I LOVE the feel, but as soon as I hit a rough pavement (and everyone that lives in SoCal knows that we have VERY little of the paved roads that are not rough!). I have no issues in AZ or NV in this setting (WAY better roadways). I checked the Airmatic completely. No leaks on the struts, or hoses, pump operates as it should......so why is this happening? Could not find the answer in the stickies, that's why I want to ask on the open forum.

The second problem just appeared on Monday. CEL came on, and my OBD tells me P0410. I researched EVERYTHING on this in the stickies (and MANY other websites given me by Google search), and checked the "smog pump" (looks like new, blows nice on the cold start, and then shuts off), checked both valves and the hoses (no cracks, nothing disconnected), and the 40amp fuse is OK too. So what else am I missing? Malfunctioning relay? (working, but "sticking" once in a while?) I must add that while I was checking the Airmatic issue, I swapped the relays (they are identical). Airmatic problem persisted in sport2 setting, and a day later CEL appeared with P0410. Is it possible that this is something as simple as a sticky relay?

I turned off the CEL (hate looking at it!). As a pilot, I just CAN'T deal with warning lights! Returned the relays to their original sockets, and the CEL is off for two days now. "Airmatic - Car too low" comes on regardless of the relay used.

Anyone has the experience in chasing this?

I'll appreciate all responses.
 

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2001 S500
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18 Posts
I had a "car too low" airmatic issue which was resolved by replacing the valve block that's attached to the pump. I had similar symptoms to yours where I'd see the issue more often in certain suspension modes.

I would most often see the problem right after getting on the expressway and accelerating to 70-80mph. I think the suspension drops a little over 50mph.

I replaced the original one with a used airmatic valve from eBay. The seller had a 30 day warranty on it I think. It's actually a pretty easy install. Don't forget to inflate your suspension before putting the car back on the ground.


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2002 S430 AMG wannabe
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115 Posts
Discussion Starter #3
Thank you for the tip.

How do I troubleshoot this valve, and where it's located? I need to find the culprit before I start replacing components.
 

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W221 & Audio Moderator
2013 S550
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10,978 Posts
The Encyclopedia has a link dealing with that. "Valve Block Replacement" under Airmatic.
 

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2002 S430 AMG wannabe
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115 Posts
Discussion Starter #5
Thanks, I read that. The problems the OP posted are not the same as mine. Now I know where the valve is, but how to troubleshoot it, and eliminate it from equation?

My observation on the "Car too low" is amateurish at best, but it seems like the car goes in the "fast and low" mode (in #2 sport setting), and it drops too low for the bumpy roads. Almost like it goes too low than prescribed by the designers. Maybe some sensors that are faulty/dirty that let it drop too low? Funny thing,.....on the smooth NV or AZ roads there is no problem! It happens only on the crappy CA roads. And it never happens in "normal" or #1 sport!

Is there a difference in how low the car would drop between the #1 and #2 sport? I didn't think so, but I better ask.
 

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2001 S500
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Setting #2 is the stiffest, and therefore the highest. So "fast and low" would actually be the highest in #2. The other thing about #2 is that the struts will have the most pressure than any other setting. Driving over rough roads at high speeds may be aggravating some leak in one of the strut seals.

I swapped the valve first because it made sense to do so and also was the cheapest part.

There are also height sensors that can go bad. I don't know exactly what mischief they can do, but I assume symptoms like yours would fit as well. There are 3 of them and cost more for one than a used valve...


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2001 S500
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The way the dealer tests the airmatic system is put the car on a special lift that moves each wheel up and down independently. I think I saw someone call it the "rodeo" test.

You can use Carsoft or sds to get realtime data from the height sensors. They'll also read any error codes from the airmatic ecu.

There is a hunk of electronics on the valve as well. I don't know whether my issue was electronic or mechanical. I'm pretty sure all the height/pressure changes are handled in the valve.


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Current 2017 GLE350, 2007 S550, 2002 S430, 1998 ML320 Deceased 74 240D, 92 400E, 97 E420, 13 GLK350
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1,915 Posts
Attached is a troubleshooting guide for P0410, secondary air injection (aka smog pump).
 

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