OK, I got the dreaded chassis system failure a few days ago. Full disclosure, it followed a period where I had the car up on the quick Jack for about 48 hours while I had the front wheels redone. I raised the suspension to the full height and disabled it before I put it on the stands. After I put the wheels back on I noticed the next day that the Front and end had sagged. Particularly the passenger side front wheel. Long story short I determined that the front passenger strut is leaking at the connection for the height sensor. I could not find any other problems and the system was acting very erratically. I plugged in my code reader and reset the codes and now the system is operating normally. I am still going to replace the passenger side front strut along with the upper and lower control arms while I am taking things apart. I still can’t figure out why I was getting the chassis system failure notice and nothing worked but when I reset the code everything worked fine. Any ideas?

 

Impossible to tell why you got the chassis system failure.
only way would have been to scan with piwis and read out faults.
Not sure what scanner you have, but 9nly way to guarantee is to use piwis, and test system.
if your suspension sagged. The chassis system failure would appear if system could not inflate it.. if your chassis was low. It would give you extremely low warning.
so error could be from being too low, not inflating well, not inflating proper shock. Etc.
read the diy for debug of suspension. Could be valve block,, shocks and valves in them, height sensors, compressor.

Based on your info, decent chance error due to front deflated. Consider replacing both shocks. Test other one and you'll know.

 

I have the iCarsoft CR Pro. The only codes I found were 002086 Sport mode level control faulty, and 00208A Sport mode faulty. Prior to the reset, the system would raise the back but rarely the front and then it quit working altogether. I rarely put it into sport or sport plus so I don't know if that has anything to do with it. I plan on replacing both front struts along with the control arms. I might as well since everything will be mostly apart anyway. I am just hoping that fixes the issue. I am looking at these control arms: https://www.fcpeuro.com/products/por...sche-970ctrlkt and these struts: https://www.rockauto.com/en/moreinfo...t=7584&jsn=838 https://www.rockauto.com/en/moreinfo...t=7584&jsn=839

 

I have developed the opinion that leaving the car in the air for anything longer than a few hours is bad for the air struts. Suspension off or not. Now whenever I have the car in the air for any length of time, I support the wheels with bottle jacks to take some of the stress off of the top o-ring and bushing. My car was left in the air for 3 days by a tire shop. When I got it back, the front struts were leaking and I replaced the bags and seals.

Not sure what you mean by "leaking at the height sensor" since the level sensor is on the body of the strut and nowhere near any air lines or the bag. Do you mean the little electronic plug at the top or where the air line goes in? Is the strut still leaking?

Edit: that Lemforder kit is the exact one I just ordered. FCP Euro has the best price. Lemforder is an OEM supplier - top shelf parts

 

It is the electrical connection at the top of the bolt where the rubber gasket is leaking. I thought the wire came from the height sensor in the wheel well but I could be wrong. Yes, still leaking. The car only has 33,000 miles and I plan on keeping it so I’m replacing both front struts in the upper and lower control arms. I will probably do the sway bar bushing for good measure because that’s the only cheap part. 4K in parts so far.

 

Lemforder are oem control arms. I would consider replacing upper and lower control arms (upper arms go bad too and if you hear creaking, etc, it likely comes from there, the bushings get torn due to age and cannot be observed, since the bushings are obscured from view.
Once you replace these, the arnott shocks are good too. Make sure you have make clean and good connection between air lines and the components they will connect to.
Yep, leaving car slammed is bad for the shock bellows. What I did is get 3 blocks of a 2x4 wood, about 4" squares, two of them are nailed together (bottom ones). the third is separate from other two, and in addition to that, I bought the rubber blocks that fit into the jack locations under the car. The end goal is having something that I can put under the front of car (at jack locations), which under normal circumstances is lower than the car, so when I open the system, the car rests on these, but after system inflates, the car is not resting on these. Just a protection for me. I lift the rear of the car using two low profile jacks.

I would advise getting the piwis. It allows you to test each component, give specific messages. FOr example, when the valve block stopped working right, I scanned it and got message saying the purge valve on the block does not stay open long enough. Sure enough, observing, I could see that the car does not allow deflating air when needed. Simple but very specific message, allowed me to get right into the problem area, the valve block. Generic scanners give generic info and sometimes are very difficult to translate into what the meaning is for the car.

So far so good. Update us after you change. Great.

 

Does the car tell you it needs the UCA/LCA's replaced - either with shimmy's under braking, creaks/groans/rattles, etc? If not, at 33k, seems like you're bringing "preventative maintenance" to a new level. Normally, the parts you are replacing last at least twice as long. Regarding the location of the leak, that's the upper bushing and its a super common spot for them to leak. Still not sure why your car popped the message initially. As was already said, if the car was too low, it would pop the "suspension extremely low" warning. It is possible the system simply had a glitch which was cleared when you blew out the codes.

When it comes time to re-inflate the bags, try to support the car to where it's slightly below the low setting on the suspension. Ciaka details a way in his post above. Then use the air-gun and inflate the bags a bit before you connect the car's air lines. Then turn the key and let the car inflate the bags fully and lift it off the jack or lift. This is how I've always done it and it works well. FWIW, I do not have a PIWIS - I've got the iCarsoft Por2. There are times I wished I'd had one, but I've been able to manage thus far. The PIWIS is an expensive tool, but a handy one if you're going to be the exclusive maintainer of the car.

 

it does rattle when on very bumpy roads. To the point where a passenger asked “why is your car making that noise?” on a bumpy road. I plan on keeping the car for a while so I figure while I have it apart I might as well do those parts since I have the rattling. I do plan on supporting the other three wheels while I work on one side of the front at a time. I also plan to lower it and inflate the bags as you suggested. I wish I would’ve known about leaving the car suspended before I took the wheels off to get refurbished. I would’ve lowered the car and supported the disks on some blocks of wood.

 

Have you tried to figure out what part is rattling? Could be just one part instead of all 4 control arms. Just trying to save you some cash even though I am wired the same way. My suspension is squeaky and I'm replacing everything. But I've also got 62k on it, so to me it's time to do them all anyway.

 

From experience in owning porsche cars, lower control arm gives you a banging noise over bumps, as opposed to creaking (like old box soring bed).
The creaking is usually from upper control arms, and often from worn sway bar bushings.
So for bangs, lower arms, creaking, upper arms and/or sway bar bushings.

On cayenne, banging is also often due to the internal shock stopper bushing. Haven't noticed this on panamera though.

There are many who have reported shock failure on their PIG after 30k miles, so it is not very unusual. The rubber seal around the top shock valve is the most common place to leak. Usually tears and air starts coming out. Hence soap spray on that area to check.
when one shock goes, you can take it to the bank that the other us right behind it

 

I did not try to figure out which specific part was causing the banging. I’ve only had this car for a year and I love it and intend on keeping it even though it can be very frustrating. I decided to just do the upper and lower control arms while I was doing both shocks. Only one is leaking now but like you said the other one can’t be far behind. Did the DIY for the lower control arms ever get posted? I could not find it. Also, I don’t see much posted on the rear shocks going. Do they not normally go like the fronts to do?

 

I cant look now, but if you cannot find the panamera one, use my DIY for cayenne turbo. Virtually identical (panamera has lots of design from cayenne). HERE IS THE CAYENNE LCA REPLACEMENT.
Hope helps.

 

Thank you for the link. Can I do the lower control arms with the shock removed? I was planning on taking out the shock and the upper and lower control arms all at once and then putting it back together.

 

You can do lower arms with shock removed yes, but to make things easier, I like doing it while something is attached to the steering knuckle. Keeps parts in place and brake hoses dont have to be dealt with.
So whatever you do, do one arm at a time.

If you are removing shock, that is the perfect time to do upper control arm (bolts for the arm are obstructed by shock, which must be pulled to remove upper arm).
Lower arm only needs to be separated from steering knuckle, sway bar and other ball joints (3 of them).

For separation of sway bar, you have to have both tires off the ground, to ensure there is no pressure on the bar, so you can remove the links.

Hope this explains mechanics, I think I would do shock and upper, then without install ing the lower arm into shock, pull the lower for replacement, then install the new lower arm, reconnect sway bar, etc.
THIS IS IMPORTANT. AFTER YOU SEPARATE ANY SUSPENSION COMPONENT BALL JOINTS, EVEN IF READJUSTING BOLTS ON SHOCK, YOU GOTTA GET NEW ALIGNMENT. Without alignment, you risk chewing tires up.

 

The other key thing to remember when doing UCA/LCA work: final torque must be done with the weight on the tires. If you torque things down with the wheels in the air, you run the risk of destroying the bushings in record time. You can do this without a tire on by lowering the car down onto a stand of sorts under the lower control arm. I stacked up a couple of sections of 4x4's.