Hydractive not working

[Casian]

Hi all,
I’m new to the forum and maybe someone already had the same issue like me.
I decided to depressurise the system in order to check the LDS level.
It was done using Lexia.
It all worked fine, the car went all the way down.
The only issue is that it won’t move.
The car has 3 settings for the suspension but the up and down buttons don’t do anything, it doesn’t even show up on the dash screen.
When I press the sport button, the ‘’sport mode activated’’ message appears.
I repeat, the suspension doesn’t move.
When pressing the up or down buttons, there is no noise from the pump, however, using lexia to check the actuators, the pump does activate, but it’s just a short buzzing noise, but that’s it.
If someone had the same issue, please let me know.

[GiveMeABreak]

Try not to keep multiple posting - I've deleted your other posts and added your picture under the original post.

As for the issue, so you have depressurised the system then topped it up to the levels between A & B as shown below only and not filled it past the indicated levels?

If this is the case then it can take a while to repressurise, but may need some pressure applied to the LDS tank to start it off, about 0.5 BAR.

Before that and whilst still on the lowest setting, bleed the system first by ensuring the suspension is on the lowest setting, and with the LDS cap off and engine running, very slowly turn the wheel from lock to lock and do not hold the wheel when you reach the lock point - just turn it back the other way and repeat this slowly for about 8 cycles, then allow the wheel to look straight ahead.

Then allow any 'fizzing' to stop at the top of the fluid. Return the suspension to the normal ride height and wait for 5 minutes or so. But if you cannot hear the electronic pump engaging, then you may have blown the fuse due to the pump overheating.

I'll check the fuse shortly...

[Casian]

Hi Marc,
The level is fine, as for the maxi fuses, I’ve already checked it and they’re all fine.
The problem is that I’ve got 3 buttons to adjust the suspension, when pressing up or down the pump doesn’t make any noise and nothing appears on the dash screen.
The only time when something appears on the screen is when I press the sport button, but the same, the pump does not engage.
I drove the car on a flat road at about 30 mph and no errors turn up, the car drives as nothing is wrong with the suspension.
I will turn the wheels from side to side as you’ve mentioned and see if that does something.
I’ve tried to pressurise the tank trough the cap’s release pressure point, but I’ve discovered that the tank is cracked at the top on one side. It keeps some pressure but when it’s too much, it’s just spitting oil.
Is there any other way to pressurise the system?
Thank you

[GiveMeABreak]

1) The pump makes no noise when switching between sport and normal modes (the electrovalves just switch in and out to ride on all 7 spheres (Normal Mode) or just the 4 corner spheres when in sport mode). This is normal. The pump only runs to make slight pressure adjustments - not continuously).

2) If your tank is cracked / shot you need to replace it - for the following reason: LDS fluid can run down the tank and onto the pump. Once on the motor LDS can seep into the motor housing and this will cause the carbon deposits from the motor brushes to mix with the LDS and form a sludge - this can then cause overheating / shorting and blowing of the fuse.

See Elis's Word Press post here for an example:

https://elisdavies.home.blog/2019/08/26 ... ditioning/

There is no way to repressurise the system apart from the pump motor.

[Casian]

Hi guys,
Thank you for all your feedback.
I’ve managed to plug it in to Lexia today, so please see the attached pictures.
If you have any guidance on what should I check first, please let me know.

[GiveMeABreak]

Ok, so there does seem to be a communication issue between the Suspension ECU and the BSI. For now ignore the last 2 faults regarding the height sensors as this makes sense if the info is not being received.

Check 2 additional fuses:

The first one is F13 ( Hydraulic Suspension Pump Cut-Off Relay), a 5A fuse in the fusebox along the bottom of the BSI arrowed.
The second is G39 (Hydraulic Suspension), a 10A fuse that should be located to the right side also arrowed and not easy to see. Don't get this mixed up with the other G39 fuse in a bank along the top (Fusebox 'A') - it is NOT this one.

[siilisxuaali]

Hi guys.

I have a very similar problem here. The other day my C5(X7) was really bumpy on the back, and once I got home I thought I check if the suspension is working fine. First I lowered the car to its lowest and that's when it all started. It wont rise up again. The car is not giving any readint to a monitor like suspension fault or anything. When I press the up or down button it says closing/opening in process but nothing happens.

I've checked all the fuses (F13, G39, and MF) and they all are in working condition. Also the LDS level is fine. I connected the car to a computer and it gives the following faults:

C1146 Hight correction rear
U1118 No connection to BSI (This one comes twice)
U2005 Triggering (vehicle speed receipt anomaly)

And also: (I don't know if related)

5FF (Was something to do with BSI as well)

I cleared all the faults and the only one that came back is the U2005.

I'm wondering could it be the pump that's worn out and have to be replaced as it's not making any sound on any point. I keep finding a lot of second hand suspension pump systems, but they all seem to be for either the Mk1 or 2. Is it possible to mount one of these to my X7 or are they somehow different (H3 or H3+ etc.. or something)?

[GiveMeABreak]

You can ignore the U2005 fault, this is to do with the car not moving when the suspension ECU is interrogated. Your problem would seem to be the rear height corrector. If it’s not sending the data or the data is incorrect it will prevent height correction taking place.

So the first thing I would do is get your height correct to sorted out.

The pumps on the earlier C5s are not compatible with the X7. The systems are slightly different. But before you even go down that road, get the height corrector sorted out. You may not hear the pump noise because there is no height correction taking place, and as I said it won’t correct the heights if there is a an anomaly received from the high correctors.

[siilisxuaali]

Hi Marc,

I got finally under my car and to check the height sensor. I noticed the dog bone is really wobbly on the anti roll bar end, but doesn't seem to be broken. (like it's moving left to right about 0.5 cm) Is it supposed to be like that? I didn't dismantle the sensor as I'm not sure if it will (-expletive removed-) up the whole system. Is there a correct procedure to check the sensor wether it's working or not. The lever on the corrector seems to be also quite stiff but am not sure if I should apply any force to it?

Thanks in advance.

[GiveMeABreak]

Please make sure you support the car independently before getting under - when dealing with height correction issues, the car can come crashing down without warning and crush you.

The height correctors can corrode and water can get inside the unit, causing the track data to become garbled or missing - so difficult to say. The clamp position of the height corrector on the ARB is crucial as this affects the height setting. If it is moved it can affect the height settings, so should be marked with some white paint or similar to note the correct position if you are planning on removing it.

The dog bone can move slightly around the ball itself (left to right) as these just snap on - but they should not move otherwise - see my diagram below: