C5 2009 Exclusive 2.0 138 hp lhd suspension fault

[Sean[C5Exc2009]]

Hi, new on here. My car is showing suspension fault max speed 90 kph. Local French Dealer, who seems to have a minimum quote of €600, says both front and rear sensors are faulty and need replacing. Both have gone at the same time he says. I’ve checked fuses and all seems to be in order. Has anyone got any ideas of fault diagnosis that I can carry out to confirm or otherwise of what the garage has said? I have an iCarsoft diagnostic tool but it isn’t sufficiently sophisticated to deal with this problem. Any tips greatfully received!

[mickthemaverick]

Hi Sean
Welcome to the FCF, it sounds like you need to have a proper diagnosis done with Diagbox to identify what is going on. In the meantime there are some threads on here where people have had similar issues and you may get some ideas by reading through some of them, this one will get you started: viewtopic.php?p=840389#p840389 Good luck

[Kees]

First start with checking the LDS level, if the car is in the lower position, you should see the fluid just at the bottom.
If this is ok, check the fuse 40A in the red fuse box behind the left headlight.
If this fuse is blow, you have a problem with the HD pomp, and sometimes you can repair this one with cleaning the brushes.
This fault comes when the pressure is to low, and have nothing to do with the sensors.
Greetings,
Kees.

[Sean[C5Exc2009]]

Thanks Kees. I checked all the fuses behind the battery including the ones underneath and removed every fuse and cleaned them with contact cleaner. It made no difference. It’s been my only mode of transport so I’ve had to use it and now the front is permanently down at its lowest so I think I may have damaged the expansion spheres and I still haven’t found the original fault. It’s very unpleasant to drive. I’ll check the LDS level in the morning. Do you know the easiest way to check if the pump is working?
Thanks again
Seam

[Kees]

You, say, that you check the fuse behind the battery, but i told you to check the fuse BEHIND the left headlight!!
Between the headlight and battery is a little fuse box, and inside is an 40 Amp fuse.
If the hd pomp is not working, most of the time, this one is blown.
The reason could be that the brushes inside the motor are messy with carbon and the lds fluid.
You can find here several post how to repair/clean this
About the spheres, they will not be damaged by this, because there are no fluid pressure under the spheres, therefore you have no suspension anymore.

Here you see the red box behind the headlamp and the battery.

[Sean[C5Exc2009]]

Hi Kees, I found the fuse box you were talking about and checked the continuity across each one. Thank you for persevering with me! The fluid level is below max see photo. The car is sitting right down at the moment. As it’s not the fuse and I don’t have an LDS leak would you say that the sensors are the problem? I also need to change the rear brake pads now as they are worn out but am having trouble getting my jack under the car. I have a gravel drive so may have to dig a hole. Any ideas? Thanks again in advance

[PaulC5]

I cannot see the lds fluid level, you have not removed the black lds tank cap to look inside. With the suspension on low the fluid should be at the bottom of the strainer in the tank neck. The off white tank that can be seen in your photo is the coolant expansion tank.

To check if the suspension pump is running simply start the engine and set the suspension height higher than it is now and if you can hear the pump and the car rises you know the pump is working.

[Kees]

@Paul: a little correction, when the car sits so low, you have to see the fluid level higher, this position is the same when you use the diagbox to lower the car in the lowest position.

[Kees]

@Sean[C5Exc2009]:
I'm sorry to say, but i wonder about your technical skills...you put a picture of the coulant tank, but the LDS tank is just before this one. Look at the pictures.

.Even on the tank you see a sticker with the text LDS !!!
When you screw of the cap and you look inside, you should see the lds fluid now around the niveau mark, because the car is in the lowest position.

The level must between a and b.

[Kees]

About changing the rear brake pads, first make contact without starting the engine, then release the parking brake, leave the contact on and disconnect the battery .
By this way the parking brake will remain of and you can replace the pads easily.

[PaulC5]

If you are going to jack the car up you are supposed to first raise the suspension to max height with the engine running so the pump runs, switch off, then slacken the lds tank cap and leave loose until the car wheels are back on the ground after being jacked up. Failing to loosen the cap can result in the lds tank splitting. Make sure you slacken the lds tank cap and not the coolant expansion tank cap having already mixed these up. If you do not raise the suspension you can end up with all sorts of suspension problems.