4.8 Air Suspension issues, EHC 74 code and compressor won't switch on

[LVR]

Originally Posted by Leicesterboy15

I could hear it releasing are through the gold valve on the compressor, this happened about 5 times until there was no pressure left to release.

Do you mean leaking at the valve or air passing through it into the system?

Regarding where to look next, there are only three things it can be, a major leak, compressor not sealing or electronic setting.

Major leak can be an air bag has popped. I was lucky and happened to be near mine when it let go so heard it happen. I replaced only the bag (not the whole strut) with some help of one of the members here. Funnily enough it was the front left which was also the one giving me the plausibility errors you're getting. I would be having a close look at the bag itself there and doing leak test, and then a close look at the connections around the compressor and check what you did is properly sealed.

As you've got over 13 bar on the compressor it doesn't sound like it's the issue.

In your pics you've shown pressure in the accumulator. What happens to remove it? Are you activating the struts?

If there are no leaks then the next step is to address that front left reading. Have you cleared errors (delete fault memory) in the module yet? Not sure if anyone here can chime in with resetting the module on INPA? I do it with Insta when playing around.

This is what I had in my ride heights.



I had to progressively adjust that value by resetting the height on that strut only (just repeating the other values on other struts) to get it back within the range of the others and it's worked correctly ever since.

[Leicesterboy15]

Originally Posted by LVR

Do you mean leaking at the valve or air passing through it into the system?

Regarding where to look next, there are only three things it can be, a major leak, compressor not sealing or electronic setting.

Major leak can be an air bag has popped. I was lucky and happened to be near mine when it let go so heard it happen. I replaced only the bag (not the whole strut) with some help of one of the members here. Funnily enough it was the front left which was also the one giving me the plausibility errors you're getting. I would be having a close look at the bag itself there and doing leak test, and then a close look at the connections around the compressor and check what you did is properly sealed.

As you've got over 13 bar on the compressor it doesn't sound like it's the issue.

In your pics you've shown pressure in the accumulator. What happens to remove it? Are you activating the struts?

The air was being released from the gold valve in the picture, when I tried to activate the suspension or it kicked in automatically the first time after clearing the error codes it would release air from this valve and then trigger the error again. I would clear the error and again as the suspension tried to activate some more pressure would be released. This cycle continued until there was no pressure left. The car was already on the ground when the compressor was at over 13 bar.