marktrav

I'm having a time trying to get my air suspension back to normal. A few weeks ago, I got the dreaded red "Air Suspension Warning" graphic on my display and over time the whole suspension settled down to the lowest point where it's bouncing off of the rubber grommets.

I replaced the air pump with a new one as the last time I rebuilt the original one and it was starting to get rather loud.

Now, the front shocks are deflated and the rear shocks are fully inflated and I can't get it to settle out even after driving it a few miles on a twisty, elevation-changing road.

I tried a few methods of overriding it, like disconnecting the sensor arms on the rear shocks to get them to deflate and the same on the fronts to get them to inflate. I finally disconnected all of the air connections at the distribution block to let out all of the air, then disconnected the battery for 10 minutes. When I started it back up, I could hear the compressor, the rear jacked up and the front stayed firmly on the rubber grommets.

I checked passenger side fuse 48, which is fine. I tried to do an Adaptation with my Durametric, but it would time out trying to read any of the 4 sensors. (I've got the original control module ending in "E.")

I've got a spare level control that I bought a few years ago off of a Phaeton (Newer version ending in "F") that I didn't need at the time so I just put it away for safe keeping. I swapped out the "E" for the "F" and re-coded it to 15511 (it was 15521) and the comfort/normal/sport and level switches lit up and worked properly. However, it is telling me that it needs to learn all 4 positions. ok, no big deal, I've done that before. Well, when I "read" one of the 4 sensors, I get an error that it can't get a reading and throws a "33" error code. All 4 sensors also throw a 77x code (774/775/776/1769) "Vehicle level sensor xxxx Faulty"

I know having all 4 sensors go bad at the same time is suspect. Is there someplace central that the sensors feed through before getting to the level control box?

Not sure what to try next. If I could at least read the sensors, I could do the adaptation, but I can't seem to get that to work.

Klaird928

I did pretty much everything you have done once before on mine. I replaced all the modules and the pump. It would not air up properly. I replaced all the modules back to the original and it worked fine after that. I don’t know why it did not like the replacement parts or why it chose to work with the original but I did not complain. I did not have the durametric so I could not see what the errors were. One other thing I did was I jacked the car up so it was not sitting on the blocks. I think it can go down beyond the point of no return. I would definitely jack up the front to allow some space for the air to fill the void.

BobcatBrian

If you look on the miessler automotive website, they sell some adapters that let you check air pressure at each air bag and add air with an external air compressor. You could pick up one of those and air up the bags to the correct amount and reconnect the lines.

marktrav

Thanks for the replies! I thought I'd get an e-mail notification, but evidently not.

Anyway, I'll try to jack up the front. This morning I went through the entire system and checked everything, including the relay under the driver's wheel. (US, Left hand drive) The pump comes on when asked to do an Adaptation, etc. But the fronts just never get filled.

It was complaining that my values were not plausible (190 in front) and then would register a "conditions not acceptable" or something to that effect. I finally got the control unit to accept my values of 130 in the front (what it currently is) and 180 in the back (what it currently is) and it accepted it! No more error codes. WooHoo! All 4 sides seemed to show the same micro-voltage and they reported level values that were all close to each other.

Except after driving a mile down the road with the familiar clown car bouncing motion the "Warning Air Suspension" came back on.

The only thing I can think it could possibly be at this point is the Pressure Control Block. (958 698 014) I never could get a reading from the reservoir or the shocks on the actual air pressure. I've seen some people show this from their PIWIS and other tools, but I couldn't get mine to show it. Perhaps that info is collected from the pressure control block? You'd think there would be a big bright red flag if the pressure control block was malfunctioning, but evidently no-one programmed that into the firmware. Maybe. I guess.

We'll see. I ordered a new one from Amazon. I opted for the $150 version over the $68 version, both reasonably priced compared to the Porsche AND VW identical part numbers for $811!

I love this vehicle when the air suspension is working. I use ALL of the settings ALL of the time. I can't imagine replacing it with coilovers. But trouble-shooting is a Phd indoctrination program!

Klaird928

What is the status of this project?

marktrav

I’m waiting on a new air control block. 26th estimated delivery. In the meantime, I got a jack that works under the front axle and I’ll try to do another adaptation with the front jacked up. I was able to get enough air that it no longer bounces off the shock bottom, but it’s still very bouncy.

marktrav

Update: The new air control block fixed my suspension. However, I can hear a slight hiss from the FR shock in Normal and High Terrain mode. If I leave it in Lowered mode, I don't hear the hiss. Any chance the o-ring blew out and not the bag? The hiss is coming from the bellows area, not the bag section of the shock.

Just in case, I'm going to order a new shock. If I'm lucky, I can fix the current one and leave the spare on the shelf for the inevitable replacement.