C5 hdi 2002 estate serious suspension fault

[WidowmakerUK]

The other morning I lifted my c5 to its lock poison to change a front tyre, that went fine no issues. When I set the car back to it normal ride height the front came down fine but the rear did not it stuck up in the lock poison and refused to come down.

My first thought was the rear switch arm had come off so I took jack out and placed under the jacking point and just took the load with it for safety reasons. Check the arm it was on and it had oil around it from the last time I serviced it. So my next plan was to check the switch to see if it was seized so I popped the arm off and moved it to a 5oclock poison I then heard a click and the pressure rush as the rear centre control valve open. With that I rushed from under the car with great speed. I then lowered the jack slightly and popped the arm back on to the switch then let the car down. Now the jack is stuck under the car as its come down too low to get the jack out. So I went to lift the car again but it flashed up on dash serious suspension fault. So I put another jack under the tow bar and lifted enough to to get the first jack out then let it down so I could get the other jack out. The pump I do not hear run now at all and I know the pump is fine as its just had a new motor fitted and was working fine.

I have tested for power at the pump and I have a live and earth there the the 40amp maxi fuse is fine and has power there. So I thought it has to be that rear switch at fault so I got a new one and fitted it but I still have the same issue.

If anyone can shed any light on this subject for me please.

[Hell Razor5543]

It is possible that the pump now has air in it, stopping it from pumping LDS fluid. There is a (little known) rule that, before changing a wheel you should loosen off the LDS cap to allow for pressure changes when the suspension is hanging loose. What you might want to do is to lower the car to the lowest setting, and then see how much LDS there is in the reservoir. It should be between the lower and higher vertical slots in the grating (you will see what I mean when you take the cap off). If it is below the lowest slots top up with some LDS (you can get it from GSF for £15 per litre), and then see if the suspension moves. If it does not, you may need to prime the pump. Although I have not done this myself, you can (after first getting the top clean) prime the pump by blowing hard into the tank (it does not need much pressure to prime the pump, around 7psi should do) with the suspension set to normal height.

Good luck, and I hope you get it sorted.

[WidowmakerUK]

It got plenty of fluid and was working fine, the code read says it a power issue, I can read all the level switches and its current ride height witch I will say it's sitting on the floor with no way to get under it now.

The coder I have used is a mega macs 50 supplied by hella.
The code it has given me is c1125 fault power circuit failure to pump,

I have power at the pump motor and I am now thinking the new motor has failed the pump was not replaced or removed from the car it was just the motor I replaced with a new one.
The lds tank is to the higher marker as I always service my car and do a weekly check.
Like I said in my first post I do not hear the pump run at all.

[citro6hydra]

Hi,
The motor in your suspension pump assembly is very likely ok, the circuit diagram for the suspension system shows the motor operated by a relay or solenoid as a switch and this is operated by the ( Calculateur ) unit on top of the suspension unit there will always be 12+ volts at the unit, the switching is in the earth side of the motor armature.

One thing, is it possible the when you have refitted the arm to the feedback unit ( Capteur ) it was in the wrong position ? as it can be swung through 360 degrees two fitting positions are possible, this can easily happen and probably more so if you are working by feel rather than visually.

ONE LAST THING PLEASE NEVER EVER GET UNDER A HYDRAULIC CITROEN, RELYING ON THE HYDRAULICS FOR CLEARANCE, YOU MAY BE QUICK BUT IS IT WORTH THE RISK ? SNAG YOUR CLOTHING LOOSE A COUPLE OF SECONDS AND ? ALWAYS USE STANDS.

AN OWNER IN THE NEXT SUBURB TO ME RELIED ON THE HYDRAULICS AND WAS FOUND SOME FIVE DAYS LATER, IT BECAME A MATTER FOR THE CORONER.

[WidowmakerUK]

It have checked the switch poison with my other 2 c5 estates it seem to be in the correct place. How ever it did flash up a few error messages the other day but they have not shown again. Abs and a few others that I think is controlled by the ecu on top of the pump. I have checked the plug it all looks good there but it could be faulty as its been a bit funny the last month or so with the rear end staying up in the air and refusing to lower itself with the control inside the car. Hence why I replaced the rear height switch thinking it was the issue when I got this error.

As for getting under the car I alway ensure there is something big and heavy under it so it can't come down on me. I have a large trolley jack for extra support as well normally placed under the tow bar.

[GiveMeABreak]

Once you have replaced the height corrector (s) the suspension heights generally need to be recalibrated. You will need more than a code reader to do this though. A Lexia will be able to first check any faults but also to allow new values to be input. There is a specific method of measuring and calculating values that are then entered into the system and these in turn are calculated by the system resulting in another value. You can't just enter a height.

I'm not saying this is the cause of the current problem, but the slightest movement in the height correctors can affect the suspension heights. If you want the procedure for measuring, post up your VIN . I'd definitely find someone with a Lexia though as I don't think these third party tools can do all that is necessary.

[WidowmakerUK]

Thanks Marc, I'll drop the vin to you shortly. This car has been a real pain it's one of the bad ones you get sometime where it will be fine then suddenly it bust again for no reason. I have just rebuilt the head due to a new cam kit that failed the belt adjuster broke off its mount and as normal it broke the cam follower arms. It has now another issue the hp rail pump has a leak from the casing on the from cover, if you look at the pump there's a small cover on front of the pump with 4 bolts in it this is wear it's leaking. Not sure what's behind that cover so as of yet I have not removed it in case some big Spring jumps out at me, was going to look for some pump details to see if the leak can be solved with out taking the pump off the car.

[GiveMeABreak]

Ok, just be careful of the high pressure fuel rail - you don't want a face full of that!

[WidowmakerUK]

Hi have sent you a pm with the vin number

[GiveMeABreak]

Hi have sent you a pm with the vin number

Ok, I'm getting a little confused here - in your 'My Cars' profile you have the car listed as a 2003 HPi Petrol Estate and in your other post:
https://www.frenchcarforum.co.uk/forum/ ... 70#p512370
you are also referring to it as an HPi which is the petrol. In this thread you are referring to a 2002 2.2 HDi estate which is what the VIN confirms. Are we talking about 2 different cars here?

[WidowmakerUK]

Yes I have 3 cars 1 petrol and 2 diesels all estate cars

I have had the pump motor off and tested it that is working fine.
I have now refitted and tested the pump failed to run.
Looking through wiring diagram I supplied A live to the motor switch and the pump ran fine.
I ran it for a short time and car started to lift to its normal ride height, I cut the power to the pump motor switch and plugged the car wiring back in after a few minutes the pump started and stopped about 4 or 5 times I then lowered the car and then set it back to normal ride height the pump kicked in and lifted the car as normal.
It is sitting normal and seems to be working again not sure what I did but it looks to have solved it's issue for now.

[GiveMeABreak]

That explains it then! Great - fingers crossed on the pump side.