I started driving my 2004 Gt a few weeks ago and all was going fine, I tend to drive the car daily around 30 miles a day on average. I have not had no issues with the suspension since I replaced the front struts with new Aerosus units last year(the car had suncore units in the front when I bought it and the bladder went on the right front). After a few weeks i got a low level warning while driving. I pulled over and checked the ride height and everything looked normal. When i restarted the car the fault was gone and I continued home. I drove the car for a couple more weeks and I got the same fault warning 2 more times and the car still seamed to be at an acceptable height. I parked the car the other night and front end had settled so the fender was about a 1/2 inch above the tire. I received the low level warning and the compressor came on but the front never lifted. I put the car on the lift, scanned with VCDS and The codes I received were Lower level limit exceed and intermittent leak. I put the car in jack mode, raised the car , removed the front wheels, and set all four down on jack stands and removed from jack mode. I sprayed all parts of the struts as shown in other post and all air lines and could not find any leaks with the car running. I unhooked the green air line from the coupler at rear valve body and got a steady flow of air out and the right front strut went down further. I also loosened the fitting at the strut and got the same result, so the struts don't seem to be completely collapsing or bleeding off. I then removed the front level sensors on both sides and cycled them with the car running and nothing happened. I'm wondering if it could be a bad level sensor on the front or if there is a way to test them or what other things i could be looking for to resolve this issue.

Thanks in advance,
Jason

 

Need more diagnostics.

If you have vcds you should be able to trigger output tests to verify the sensors behaviour.

You could log the reads from sensors thru measuring blocks - try go high - normal - high etc.

Finally you can always retry the adaptation to see how the car will react to your real measures.

You say you checked all the lines for leaks? end to end??????

Have you sprayed the valve block?

If you guarantee you completely checked for leaks and you absolutely sure you dont have any then basing on info that you got the false signals "low" when it dissapeared after off/on - it may be only electric cause - sensor(s) issue or module defect.

Pls report on your next steps, copy/paste diagnostic data and inform what helped if problem was solved.

 

Sorry for the delay, life happens to get in the way of working on toys. This is the original codes I have:



I attempted to trigger output test but this is what I got when I went through each one, the results where the same:



I then tried the adaptation but the controller would not accept the security key, I tried measuring blocks and basic settings and received error codes.


I sprayed the valve block and did not see any leaks. The compressor does come on for a minute when ever I cycle the ignition key. I also disconnected the line for the rear struts and bleed down the rear suspension and that did not come back up after cycling the key or running the car for a while either. I’m not sure where to go from here. I am still learning vcds and believe I was doing all the test correctly, just not sure why I am getting the errors.

Jason

 

you went thru whole sequential output test procedure and it successfully passed? you saw on your eyes the reaction of the suspension (change hight, pumping or releasing the bags at given step?)

and basically all works fine - you can lower or rise the car thru button?

the only issue you got is that you have such errors as you mentioned from time to time?

 

Yes, I went through the whole sequential out put test and it did nothing, It did not level, raise or lower any of the four corners .the suspension is not reacting at all, the compressor idoes seam to run like it should and only comes on for about a minute when it does come on.

Jason

 

but you cleared the errors first? did they reoccur immediatelly after clearing?

 

Yes, I have cleared the codes multiple times and they come right back on.

Jason

 

not good - you are saying it does not have leak - computer is saying there is a leak

i would expect that output test still should go thru sequence and you should get failure on given steps to allow you pinpoint / narrow down to the real issue

however i am not the programmer of this algoritm and speculating that it may not do anything just because the cm already fires errors with leaks so the o-t are now not fully operational

being in this situation i would get a swap of the cm and would try - there is nothing i could put a closer eye reading that you physically confirmed no leaks and that there are no sensor errors.

i had a problem with the air suspension - the system gone crazy because of battery low voltage/current - so there were concrete errors from concrete sensors - both leveling and acceleration - if you have sensor problem it should fire appropriate error for sure

... i would swap module unless you have battery issue - you can be fooled you have 12+ volts but in fact there is no current / low current and you may get insane reactions of the car - you can also check plug for corrosion etc


ps. you are absolutelly sure sensors are in place and arms are connected - all of them?

 

Yes, all the sensors are there and connected. Where is the suspension control module located?

Jason

 

in lhd - interior - under the side panel - left side rear