I found a x350 that I decided to bring home and get up to speed.

It obviously had a suspension issue since one corner was way too high.

My portable scan on-site showed a few DTC's that looked voltage/battery related along with the C2802 or 3 and a cats/sensor C1429 (that may not be exact, but it's close).

I hit the forum sets pre and post purchase, got ahold of Mr. Andy, and went from there. His advise was to resolve the strut sensor error and then worry about the air supply.

I bought the PTFE ring anyway. Showing 145K, the vehicle docs cover a bunch of suspension work done a couple of years back, at an Indie.

I did get all the necessary topix copy and did the point-to-point for the, passenger side/right side/non-op side, front spring/strut error.
I thought I saw bad resistance readings to the ASU, but that cleared with revamped cables. (I wish I knew then about the 22 pin, white connector under the rear seat soundproofing.)
Time to get creative. I saw a post about 1/8" IPS fittings for the plastic tubing runs, and sure enough, by fitting 1/8 schrader valves and tubing caps, I could isolate the mechanics of the struts themselves.

Right front is/was a Arnott engraved Continental, 2 and a half years old and hosed. It will NOT evac. It is stuck at least an inch taller than others with no connects.
I wasn't the purchaser, the indie was, so no warranty favors for me.

After repeated covo's with Arnott and RMT and ebayer's, I settled on RMT for the replacement passenger's side spring/shock. The Arnott badged existing, also developed an oily sheen on the shock itself, so both components were past iffy.
(My guess is: it was battered to death.)

Problem is, a silly one inch differential, isn't the matter. The matter is 5 inches or ~125 mm. Left to right difference at wheel well height: 5 inches.

It didn't take long to understand this version has but one front height sensor... and a solenoid actuated valve block with a port to each corner... hmmm...

Since I was about to dump air anyway, I tried to find another valve block to substitute, since that was the last best switch, before I was going to invest in better diagnostics.
That next valve block may have been battered worst than the first.

But basically after jacking the other three corners to visually commiserate with height sensors and their attachment points, the car now had an even more extreme attitude.
The drivers side was now much lower than when I started, and the front right corner was heading for the moon. This is with very, very little driving to settle the suspension between lifts.

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My search fu has but a handful of such issues listed and I have not seen one taken to resolution. Although there are a couple of posts here that get awful close.

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I have managed to load clean XP Pro SP2, with no net access, and a copy of SDD v131 or so, the seller has been communicative and helpful. His distro has an GUI and the install was flawless and seems stable. Windows thinks my cable is DrewTech Pro so I loaded those drivers.

I followed Don's advice in sister threads about dealing with the aluminum ground points, at least in the trunk. (I also cannot find a point under the passenger side rear carpet.)

The SDD scan shows the same DTC's as my Autel 808 pro, so consistent is good.

The execution fails as others have, following any SDD recommend that involves leveling; ie: invoking the pump, is a never-ending repetition of trying to kill the new PTFE ring

That means, dumping axles, pre-geometry, height calibration are pointless, and require an abort that never responds either. The XP three-finger-salute to EndTask is your friend. Not Good.

You can do the customer mode and transport mode routines. They both finish as 'test completed' but nothing happens. The body doesn't move.

So I followed a recipe in another thread, that seemed to mention I could get a C2780 if I unplugged all the Wabco ASU connectors, not just the last yellow one for checking my sensor point.
It did. On the next run, under extras, I had the ASU calibration option.

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I hinted at it, my gut when buying this car was that a new battery was in order. It 'looks like new', but I finally found the date stamp and it's over three years. In our heat, on cars of this calibre, it may be passed it's use date. I'm ordering a new AGM this weekend. Unless there is some benefit to the flooded acid ?

I do have a PS, that should have no trouble keeping up. I have a voltage pot on it with some limited range. It was setup for a more cantankerous scanner, for another make, that may like a slightly lower voltage. My plan at this point, is to do what I can to keep the upper right SDD battery status icon : Green.

That said, my attempts to return the ASU to normal failed.

I decided to continue, after the SDD warning, since another had a bit of success in doing so, and so did I. The emphasis on bit.
The program warned that it found an error in ASU. I went back and took a photo, it looks like an exception addy, but I am out of my league here: 0x6780. (That may be 0x6790.)

The software is then nice, polite and stable and mentions that it can not clear all the DTC's. I should have a look, it implies. There is only the one C2780, that is related, the others are DDM, probably the mirror, the rear seat is out, so... just 145K mile car accessory DTC's

So, I let the ASU rebuild continue for a bit, and it tried to level. I aborted, AND upon inspection, it looked like the drivers side rear was up some. Feeling brave I rolled her around the block.

The rear height was back to almost where it was when I brought her home at purchase. The driver's rear was up two inches from pre-scan.

So I can drop front and rear axles from the valve body. I can probably or will definitely sort the battery and voltages for optimum 'programming' or SDD's version of it.

In looking over the logs, it does look like it was using files to return ASU to 'as-built' .

I can get VID map without incident, but I don't know what is suppose to be where, so I can't read it.

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So there are a few threads around that get about as far as above.

Mr. Cambo does a yeoman's job of getting a fellow sorted in this thread, AND my curiosity is piqued by Post #65

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For those that have toyed with this, am I missing something?

Can SDD sort this ASU or a replacement, or do I need something else?

Thank You.

 

Okie Dokie.

As part of my journey, I did get a used replacement ASU / ASM. No Joy.

It behaves exactly like the original. I started SDD immediately after replacement and tried to reconfigure the new-to- me Suspension module in 'automatic' mode.

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So I went back and reinstalled the replacement valve block, I became more convinced it was in worse shape than the car's original.

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By this time, I've run the compressor enough to get a pretty good understanding of what's going on...

As a controls guy, the system operates with a minimum of feedback, so our troubleshooting is tough, and the documentation I've scrounged, leaves more questions than answers.

Actually that hints at what we're seeing. These cases are not frequent and they are not in SDD's 'symptoms' tree.

OK, Ford decided to cut to three height sensors, but keep the 4 place valve block. (Just firmware delete in the ASU. Retain that Webco box.).

I'm guessing that's to facilitate the exhaust loop. The lowering. My problem.

So, here's what I think myself and others are really seeing: There are NO leaks. These are NOT height sensor problems.

Just the opposite. We are tight. Real tight.

The nearside where the front height sensor is, is either not raising or not raising properly. We don't know what that is.

So... the off side just keeps going. There is nothing, nothing to stop it. There's no feedback loop. It's all passive.

And that's fine... until it's not.

So I have become imitate with all the lines and connections.

I finally pulled the bad Arnott out of the garage and stuck that on the near side. I figured it was stuck on high so at least the height sensor might like that, and maybe I could get an ASM reconfigure completed..

It almost worked. The car was almost level, it was obvious that the near side was an inch lower up front but the other three corners were good.

Wait a minute. How come the shock that was jambed an inch to a inch and a half high on the passenger side, is now an inch low on the driverside? It was standing on it's head in the garage, Gravity?

Then, it got worse. Now the Broken Arnott was acting exactly like the driverside I replaced. It's not raising at all.

Note how that looks a lot like this thread: ASM Problem

I'll spare the blood and guts. The Arnott shock valves are crapware. I have two that failed at about two years after install. Your results are flaky because these valves are barely there.

The shocks both show an oily seepage about the air spring boot, as well. One on the top, the other showing at the bottom of the boot. That's the shocks themselves leaking. Both of them.

The mysterious chrome cones on the top, that ain't factory, are rusting... under the hood, in a garage, at two years.

They do a nice job engraving the aluminum boot shroud, I'll give 'em that.

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Bottom line: SDD is not needed, and is of faint use in this sit, at least v131 for this vintage is.

There aren't any DTC's for these valve troubles. You'll just see the ubiquitous, you're killing your pump: C2820 or C2830 . Or 'hey your car's too low'...

What you need is a known-good air bag valve, so you can get the bladder up in the proper time to the proper place.

If you're just starting to pull your hair out, on your air suspension and want to see what these little boogers look like, I'll point toward Kyle's Fixing Stuff

He's got an easy-to-find color-code list for the valve block and he's done the homework on the o-rings, plus the nice pix of the air valve.

 

EditHi Renovator,

Thank you for your very detailed posts!

It's late and I'm very tired, but do I understand correctly that the bottom line of your diagnosis is that when the Arnott pressure-retention valves fail, they no longer maintain the proper minimum pressure in the air spring to prevent collapse and possible damage of the bladder, but instead, they behave like one-way or non-return valves, so when the ASM opens the relevant valve in the valve block to release pressure from the air spring, the failed pressure-retention valve does not allow air to escape from the air spring?

If I have completely misunderstood I would be grateful for clarification.

Cheers,

Don

 

Don B, thanx for pouring through those. I realize the risk in slathering them on like that.

In general if I don't make it as clear as we like, it's 'cause I don't 'know' and am begging the question.

Here. it seems to me, that I have both situations. And it may have switched mid-stream.

What I do know, is that I had an example of a spring not evacuating. That spring was on the passenger side when I brought the car home.

I had no idea how these worked. I have talked with representatives of all three principles as the saga continued; an old line jag dealer here in Houston, RebuildMasterTech and Arnott.

I'm not sure what bits of info I received where, is why I mentioned that. Both Florida outfits are real busy and getting tech's from the back to go on an easter egg hunt is tough.

So I did learn there was a valve in the air spring and the idea of doing a hose dance at the rear valve block made sense.

In these first rounds, it became obvious I could not drop the offside corner all the way down.

And with the car up, I could see the oily residue, so I decided to get the replacement from RMT. They seemed more attentive, BTW. (Arnott had their warranty position, and I wasn't a part of it.)

With the new spring / shock the lift was seeming almost exactly the same. (For those just messing with suspension headaches. This is not easy to ascertain. You really need to get a comfortable method to measure the corners and keep notes over time.)

But I could, and still can get a full drop by evacuating at the solenoid valve block.

As you do and I now know, trying to add air from another source is gonna be a challenge because of the pressures involved. So, verifying what the little air valve is doing independently, is tricky.

This is the knub that almost answers your question. Running out of attempts, I throw in the jambed-on-high old Arnott on the drivers side.

And on the second trial it dumps, all the way down. It has now done a complete 180.

BTW, the passenger side / RMT is always something like 3/8" higher.

As I'm messing with the fill fittings under the hood, I apparently got both sides tight enough and when I went to loosen, both the RMT and the old Arnott air valve loosened at the valve to spring connection.

I figured, it was a sign, and time to pull those little jewels.

I didn't detect any air escaping from the Arnott side, but there still was a bit in the RMT side. (I think I read 3 atm, for residual support, so that makes sense.)

I have no knowledge of these valves but, it has to act like a pressure regulated check valve on the low side, and hold suspension on the high. (I'm guessing, since we can adjust all four corners through SDD?)

(And there is just that one pressure sensor on the valve block and that looks like it's in the cut to the white compressor line, which makes sense for evac.)

So, yes. I have at least two bad air valves and they have failed in both modes.

They have blocked air flow in.
One appears to now release to zero.
Up until a few days ago. It held at least an inch and a half high, fully disconnected.

There is NO consistency.

(It's why it looks like electronic module corruption, at various points.)

I think RMT uses the old valve. I don't have part numbers to compare to, but it has patina.

When you consider what that little machined and swaged, brass casting is being asked to do, using a reputable part, even used, makes lots of sense.

Admittedly, it's gonna be tough to find replacement air valves.

The point here, is that SDD and conventional wisdom is going to have you looking at solenoid valve blocks and ASM's. The time and effort to install and configure the modules won't be taken lightly. And it won't make any difference.

(I have a Bilstein spring/shock enroute. So, all three will be on-hand.)

 

Woot, Woot, it's sorted.

Now that she levels, I'm hoping my SDD install will do an uneventful ASM reconfigure.

(As others have reported, it looks like my previous aborted reconfigure attempt did just fine.)

 

Hi Renovator,

Please don't leave us hanging! How did you get it sorted?

Cheers,

Don

 

Our analysis was spot on.

Two bad brass valves. The new to me Bilstein got the proof of concept working.

Immediately the car started to behave like most folks report their's do.

So this evening I ran SDD and had to get into an old session to get the ASM reconfig option, and it ran...

I went ahead and tried to lower, in the reconfig routine, even though in Cambo's first post of the lowering thread he intimates a two step is best.

I was within 16 mm left to right on the first correction.

I actually lost a little ground by not ending at that point. SDD reported it didn't config, but it's working well.

So no yellow or red lights.

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Something I do not understand for the epilogue:

In the epistles above, the right shock is jambed on high. It became worse as I messed with it. (I was looking at the original pix at purchase.)

But it was jambed and when fully disconnected held the far side up at least an inch and a half.

After I put it on the left side to try and test fittings. and grab the height for the sensors... it collapses.

I had it stored upside down for the month or so waiting on modules, software, cables, whatever.

So... yesterday it gets pulled. I had the known good RMT valve in it. That valve goes back to it's home on right side.

I'm picking up after the shock swap, and I look down, as I'm heading into the garage, carrying an upside-down dead Arnott... and it's bleeding. Dumping what looks like my arch-nemisis DexCool, all over.
There's about a forty foot trail heading back to the car.
That ain't supposed to happen, is it.

So as my stomach starts to churn, I grab a swab and wipe the topside port of the valve that was on the Arnott.

It's dry. I have not seen any liquid or orange residue at any of the valve block ports in all the fitting removals there.

The effluent felt oily, but it dried up quicker than tranny fluid. It defiantly left a residue and didn't appear emulsified, but that was a lot of fluid in that air chamber.

I think I know what lubed the valve into opening for the subsequent collapse after being jambed up for what may have been a couple years.