Citroen C5 Suspension Fault

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B3LLN
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Citroen C5 Suspension Fault

Post by B3LLN »

Good afternoon all

I recently purchased a 2009 Citroen C5 2.0 HDI which has "Suspension Fault" on the dash along with the service light. At the time the car was running perfectly but after I put some load in the boot the suspension dropped and is now at its lowest position bouncing along like its on clouds! I have done all the usual checks of fuses, including Maxi Fuse and these are all fine. It looks it the ECU and the LDS tank are pretty new on top of the pump but there is no noise or movement coming from the pump. If I select the Sports Mode Activation button between the front seats, the dash says its activated but nothing happens, plus the up and down arrow buttons in the car and in the boot do not do anything and nothing appears on the dash. I have removed the power supply to the pump and there is current there. The car also shows ECO mode on a regular basis which I believe may mean it requires a new battery but I was not sure who this would hinder the suspension. I have today had a local garage put their tester on the car and was given the following error codes: U2005, 53256, 53257.
I have had the car up to allow the suspension to fully extend into the highest position and then on lowering the car back down the suspension gradually dropped to the lowest position again and there has been fluid coming out of the LDS tank lid but this is now fully tightened.

Any help here would be great as the wife is desperate to get her car back!

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GiveMeABreak
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Re: Citroen C5 Suspension Fault

Post by GiveMeABreak »

Those aren't recognised PSA fault codes (53256 or 53257). U2005 is a standard ghost fault when the suspension / ESP is being diagnosed by the diagnostic tool and can usually be ignored. So can't help you with those other 2 fault codes.

You should not have any fluid coming out of the LDS tank - if you have it is an indication of either the LDs tank being over filled, or the suspension cap not being released and put into high position BEFORE the vehicle is lifted up off the ground with wheels hanging free.

LDs should be checked with the vehicle on the LOWEST suspension setting and should be between the 'A' & 'B' marks below:
LDD MK III.PNG
LDD MK III.PNG (105.55 KiB) Viewed 115 times
See this advice:

viewtopic.php?t=62058

So you need to ascertain if the pump is working or not. If there is a fault with the height correctors, then NO height correction will take place and no sport mode either.

Regardless, the car should not bottom our or sink like that as the electrovalves would prevent this. So if that has happened, it may be the rear central hydraulic block valve:

See my post here with link and the response from another C5 owner:

viewtopic.php?p=666810#p666810

B3LLN
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Joined: 23 Dec 2020, 12:28

Re: Citroen C5 Suspension Fault

Post by B3LLN »

Thanks guys. Ive had the pump out and have it working on the bench now. I have reinstalled the unit and have applied a direct 12v current to the pump and it is running and I can pressurise the system but my lds level is low so waiting on a delivery of this and will feed back

B3LLN
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Joined: 23 Dec 2020, 12:28

Re: Citroen C5 Suspension Fault

Post by B3LLN »

So sorted the fluid and again was able to run the pump when supplying a direct 12v DC to the pump. This did not cause the suspension to lift though and the button function remained the same, i.e. I can press Sports Suspension Mode and it tells me that it is activated/deactivated, but when I press the up or down buttons there is nothing including nothing on the screen. I have carried out a service reset on the dash but it just says Suspension Fault again and nothing changes. I am not sure where to go from here now?

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Re: Citroen C5 Suspension Fault

Post by GiveMeABreak »

If you are getting a Suspension Faulty Message, then there is another problem. It would help if it was diagnosed with Diagbox as not all code readers can interpret the manufacture - specific fault codes.

Although the pump itself may be operating, that will be just the pump. The BHI (Built-In Hydraulic Interface) also consists of the suspension ECU and this is obviously not happy with some part of the system - either the height corrector data or another issue, which is why I suggest Diagbox is used to interrogate it.

When the system has been depressurised (as in when you have removed the pump) it can take 5 minutes or so for the system to re-pressurise - and needs about 0.5 Bar of pressure introduced into the LDS tank to get it going as it were.