4.8 Air Suspension issues, EHC 74 code and compressor won't switch on - Page 2

Leicesterboy15 · #11 03-20-2019, 12:47 PM

Quote:

Originally Posted by Paulpen

From a quick look (im at work) the reservoir pressure screams you have a leak or a dead compressor to me.

It could be but it would need to be a generic leak as all 4 corners dropped at the same time. When I first replaced the compressor the pressure was at 13.8 bar but every time I cleared the error and the compressor tried to kick in 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.

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LVR · #12 03-20-2019, 09:20 PM

Quote:

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.

SlickGT1 · #13 03-20-2019, 09:33 PM

I’m going to go with your compressor is shot. You can also reactivate the ehc2 with Inpa by clearing the errors while in that module. This will activate your switch and try to air up. I have a feeling your pressure switch in the compressor is shot or stuck.

Do you have your original compressor?

Also. Reset errors and make sure you watch the compressor. See if you have a leak somewhere by it, or in it.

Leicesterboy15 · #14 03-25-2019, 07:39 PM

Quote:

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.

Leicesterboy15 · #15 03-25-2019, 07:42 PM

Quote:

Originally Posted by SlickGT1

I’m going to go with your compressor is shot. You can also reactivate the ehc2 with Inpa by clearing the errors while in that module. This will activate your switch and try to air up. I have a feeling your pressure switch in the compressor is shot or stuck.

Do you have your original compressor?

Also. Reset errors and make sure you watch the compressor. See if you have a leak somewhere by it, or in it.

I still have the old compressor and I've cleared the codes a number of times but as soon as the suspension tries to activate I can hear the top part of the compressor clicking (the video in my original post) and the it throws the same error again.

I've dropped the car off at the garage and will report back with what they say, I hope they manage to diagnose the problem, I need my car and my wife off my back!

Leicesterboy15 · #16 03-30-2019, 11:01 AM

So the saga continues, the garage diagnosed the problem as the fuse panel, they bypassed the panel and managed to raise the car so a new one was ordered from BMW for £86. I think they are talking about the blue fuse panel located in the boot floor by the rear seats but I will confirm.

Then the discovered that one airbag was losing pressure over time so to save the hassle I got them to replace that at around £480 all in. Now they are saying the car keeps losing its calibration settings and drops as a result. They mentioned something about a valve setting that needs to be set if the compressor is replaced (which I replaced earlier). They said it accepts the settings and the ride stays level but as soon as you drive away it loses the settings and drops again.

They have now tried something different and it seems to be working (will confirm what) but the tech is not 100% sure its resolved so they are going to let it sit over the weekend and see what its like on Monday.

They also said they have another X5 with the same problem so I am wondering if they are making the same mistake with the calibration on both cars?

While it was there I got them to replace the expansion tank and do a full service, bill currently stands at about £1000! When they told me about the fuse panel it was a lot cheaper to fix the suspension than I was expecting so I got them to do the other bits to save me having to do them, little did I know at the time they were going to find other issues!