the_duke

I'm not sure what else to try at this point. I just came back from lunch where I drove about 20 miles of stop and go through town. No error light and wow comfort mode is comfortable when it's working.

I'm open to suggestions on what else to look at. The system is leak free, compressor is quiet and when it's in the mood it performs an output test with no issues. I might add that yesterday I not only had the yellow light but the green low light even though the car was at normal height.

I bought this car at the right price so if I spent $80 on a control module that it didn't need I won't be too upset.

I need to get the suspension fixed so I can move on to fixing the ACC and a couple little HVAC issues.

JohnnyJ A6Q

Duke,

When I picked up the 04 in South Miami back in 11 with 95000 miles on her, the 1200 mile trip home started out just fine, but after about 2 hours or so of cruising both lights came on, first the green then the yellow, and then both together, I made a few stops to check over the new ride for safety sake and all was well again, until an hour or so down the road, then later it was fine from SC through VA, but from WA to NJ it was a hard ride in the rain with 4 bald tires to boot, BUT the next week or so at home with just 30 miles a day all was fine, then it started all over again, and it was the compressor, at first I thought it sounded right, but I was wrong, then Mister Bally said to check the magnets, WELL with them fixed all was good, although I did replace the compressor 7 months later when I was selling it, I did not feel right leaving a glued unit in the vehicle.....
Plus I picked it up used off EBay for $90.00

the_duke

Bagpipingandy kit is on it's way. When I pull it to do the rebuild i'll check the magnets. I think my new (used) module will be here before my rebuild kit so i'll likely change that first.

Johnny, Did you have any codes when you were having issues? Mine still only has the one code and I would think that It would have an overheat code or something.

Mister Bally

The magnets are retained by an adhesive that can fail depending on the severity of the vehicle's operation. I know a little bit about these compressors. I prefer not to post all of the reasons publicly.
Are you sure you are looking at a genuine WABCO compressor and not a knock-off? Is the case painted black?

You can ignore my posts as I won't be offended.

mishar

Those codes do not look like VCDS ones. You need original VCDS scan. It will tell more. Post it here. Replacing module and rebuilding the compressor could easily be waste of time and money. If you keep on fixing problems that way you will hate your A8 in a no time.

the_duke

Mishar, Those are the codes from VCDS. I bought the cable from Ross-Tech when I bought the car. I used VCDS lite on my A6 but obviously won't work for the A8. I can post a complete scan if you think it would help.

This is from the Ross-Tech site:

01487 - System Function Test: Implausible Signal
Possible Symptoms
Malfunction Indicator Light (MIL) ON
Possible Causes
When found in Control Module for Level Control (J197)
Internal Error in Control Module for Level Control (J197)
Control Module for Level Control (J197) faulty
Special Notes
When found in Audi A8 (4E): Level Control (J197), this Fault Code can have several different Causes but by clearing Fault Codes most of those will be reset. Switch OFF the Ignition for 5 Seconds and then switch it back ON again, now clear Fault Codes and re-check for Fault Codes. If no Fault Code remains you are done. If the fault code remains, switch OFF the Ignition for 5 Seconds again and then switch it back ON. Now wait 5 Minutes before re-checking for Fault Codes! If after these 5 Minutes the Fault Code remains you may need to replace the Control Module for Level Control (J197).

GradecEngineering

Since your'e so familiar, do all D3 vintages use the same exact compressor? I recently did some work on the original Wabco compressor in my '08. My magnets were held in place by springs. There may have been adhesive backing also, but there are certainly springs that remain in a compressed stated which force the magnet away from the armature. Here is my own picture in which I have highlighted the springs. I tested the springs and they were certainly in a loaded state.



As an engineer, it would seem quite silly to use adhesive in an environment which experiences such heat cycling. I'm guessing that maybe they did away with the adhesive in the later models. That is why I ask if all the compressors on D3's are the same.

As far as ignoring you, I would rather pick at your brain. I prefer explaining my statements rather then giving "trust me" as a technical explanation. Since I have no financial motive here, I will provide any information I have to help our community.

Mister Bally

There were enhancements made to the compressors built during 2007 forward including the springs you see.

WABCO does some pretty silly stuff from time to time. George Westinghouse rolls over in his grave every so often.

Keep this in mind; The FIRST part that failed on my 2004 A8 was one of the two WABCO parts in the entire car.

Take a guess what COmpaNy I work for..... As an engineer for about 30 years.

the_duke

Well the new suspension control module arrived yesterday. I installed last night and my suspension is fixed! In my case anyway the info on the Ross-Tech site was dead on for my fault code.

In other news I reset my ACC sensor back to factory defaults and now my cruise control works. unfortunately it detects the car in the right lane and not the car in front of me. But at least I have working cruise until I figure out how to calibrate it. It just won't let me pass cars on the left with the cruise on. Not that we have that many 4 lane roads here in rural MT anyway. Most of my passing involves foot to the floor and crossing the dotted line.

Thanks everyone for your feedback. I'm still waiting on the Bagpipingandy kit. Should be here this weekend. I'll get it installed and glue the magnets while it's out.

jmungar

where did you get the used suspension control module? the dealer wants $1500 for a new one. my car is acting like yours was and I am thinking it may be the problem.
Jeff