New C5 owner with a few questions already

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aerodynamica
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New C5 owner with a few questions already

Post by aerodynamica »

Hi all, I recently acquired a C5 Exclusive with a couple of problems namely non functional wipers. I've read a few threads on here about it and I think (hope) that's in hand now.

There's a bit of a knock at the front right when taking up drive and sometimes a slow turn so I reckon inner bushings? still to confirm that.

Anyway! main point,
I'm new to Hydractive 3 suspension but pretty much breathe LHM :-D and I want to ask about the H3 system. It feels quite soft overall and when stationary the front is as soft as my Hydractive Xantia but the rear, though soft seems shorter in travel and I wonder if the spheres are duff. Trouble is I don't know if they are because I don't know what they're meant to be like! Can anyone describe how the rear should be? bit subjective I know ha, but keen to know!

Other suspension question is should the suspension change to stiff springs a time after closing and locking the doors like the Xantia and XM do. On my previous 2 XMs (Hyd 1 and 2) and the Xantia, the click noise after 30 seconds tells you the suspension has shut off and is in stiff springs - a push on the wing confirms. The C5 however seems to be permanently soft even after the doors are closed and locked - kind of the opposite to hydractive 1 and 2. Is this supposed to be the way or have I got another fault..

So far really like the C5 and I'm delighted to find that the Lexia3 talks to it unlike my Xantia. The scan says the rear height sensor has a permanent fault although it does actually seem to work when you sit in the open rear hatch. Also shows the BSI has had an 'unexpected restart' which sounds ominous but I don't know what it means yet.

Also need to change a daylight running bulb that the owner's manual says the dealer has to change?? Surely not!

Final question: there was a vast symphony of warning chimes and the order to put the transmission into P. It seemed to be related to the rear passengers not having their belts on... only problem was there were no rear passengers! My rucksack was on the rear seat and after I moved it the red dots in the ceiling panel stayed on until I tapped the rear seat squab a few times. It also seems to sometimes remain lit until a few seconds after moving backwards in reverse. Is that normal?

Not much then really :lol:
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KennyW
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Re: New C5 owner with a few questions already

Post by KennyW »

Graeme,

Daytime running lights(DRL’s) can be reached if hands are small but otherwise it’s partially remove front bumper for better access.
DRL’s held in plastic holder in unit.
To remove T30 bit IIRC 1/4 turn clockwise and pull out. To fit opposite of removal.
I replaced mine with LED bulbs.
As to the suspension I’m still learning when Marc is online he knows much more than me.

What type of engine , saloon or estate obviously an automatic from your post.
The seat belt lights are quite sensitive and my rucksack triggers the light. I just ignore it.
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GiveMeABreak
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Re: New C5 owner with a few questions already

Post by GiveMeABreak »

Hi Graeme

Suspension-wise the H3+ system used on the X7 is completely different to previous incarnations of the system. The suspension ECU incorporated into the BHI (Built-in Hydroelectronic Interface) handles all the suspension functions on a 4 cylinder engine (6 clyinder engines have height correctors on each wheel and an additional suspension computer) and uses a series of inlet and exhaust valves within the hydraulic block to control LDS flow. They rarely sink much at all overnight and the electro pump only runs occasionally to maintain pressure when needed.

The suspension is linked to the RCD circuit, so when the fob is used to open the doors or a door is opened the BSI triggers a request to the suspension ECU for height correction check and adjustment if necessary.

The BHI handles:
  • The electropump unit and its electrovalves
  • The stiffness regulator electrovalves
  • The vehicle ride height
  • The stiffness
There are 7 spheres on these, with 1 centre sphere at the front and 2 at the rear in addition tot he 4 corners. These 3 are responsible for switching in all 7 spheres for normal driving conditions or cutting the 3 out for sports mode.

The suspension on this model adapts the comfort, road holding and heigh according to the following:
  • Vehicle speed
  • Steady speed, straight on
  • Turning and steady turning
  • Braking and acceleration
  • Vehicle load
  • Road conditions
  • Type of driving
  • Driver request
The computer controls the sport mode directly as driving conditions dictate, but the user can switch it to Sport setting, which lowers / alters the thresholds for the sport mode, so it will switch to and maintain this mode more frequently.

Back to you issues with the spheres - If originals, these will be coming on for 14 years old now, and although they are very robust with a very long life, they may well need replacing. If you do intend on keeping the vehicle, I would recommend original spheres. These new saucer spheres are not designed to be re-gassed. OEM originals will give very long service life, although more expensive.
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Re: New C5 owner with a few questions already

Post by aerodynamica »

Thanks guys! Always a great source of knowledge here!

I think the spheres will be original so I'll probably change the 2 rear softness pair first.

It is one of the older C5s and was fairly cheap but it's such a wonderful car that I'll going to take the problems on the chin. I've had a look at the steering shaft through the wheel arch that rusts and despite my best efforts I cannot see it properly. I'll have to remove the rubber bung in the floor. I'm prepared to replace the rack and modify with an extra rubber cover (I've done my homework 😆 )

Have both wiper motors out and the driver side one has a manufactur date of 2017. The passenger side is 2008 though so I wagered that was the duff one.. I just refitted the driver one for now. I've opened the cover off the passenger motor and the little board looks damp and corroded. I'm surprised they haven't potted the board but that's PSA..🙃

task now is to find a wiper motor.


Thanks for the help!
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Re: New C5 owner with a few questions already

Post by aerodynamica »

KennyW wrote:
04 Dec 2021, 22:59
Graeme,

Daytime running lights(DRL’s) can be reached if hands are small but otherwise it’s partially remove front bumper for better access.
DRL’s held in plastic holder in unit.
To remove T30 bit IIRC 1/4 turn clockwise and pull out. To fit opposite of removal.
I replaced mine with LED bulbs.
As to the suspension I’m still learning when Marc is online he knows much more than me.

What type of engine , saloon or estate obviously an automatic from your post.
The seat belt lights are quite sensitive and my rucksack triggers the light. I just ignore it.
Hiya Kenny, it's an auto (so at just over 100k miles I'll begin the long process of changing the trans fluid...) and tourer, in a fetching grey colour 🙂

I actually think I know what's aggravated the seat belt warning.... I have the rear seat folded down because I'm storing the long plastic scuttle in the boot while I wait to source a wiper motor. I didn't remove the headrest and I think that's squashing the seat squab against the driver seat back. Of course I could be wrong there ha
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Re: New C5 owner with a few questions already

Post by jamescarruthers »

Hey Graeme,

Nice to hear from you again. Hope you enjoy your C5 (X7 or Mk. 2?), they look like a nice car.

Did you see yours and mine old BX A966 XRL had the front cover and a few pages in a classic car magazine recently? I didn’t buy a copy and have forgotten the name of the mag— long story!

I’ve got my C6 in at Pleiades for a sphere regas; they can do C5 saucer sphere too. They are built without the top recharge point but Pleiades add them. Just incase you fancy a cheaper option than replacing all the sphere.
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Re: New C5 owner with a few questions already

Post by aerodynamica »

jamescarruthers wrote:
05 Dec 2021, 11:01
Hey Graeme,

Nice to hear from you again. Hope you enjoy your C5 (X7 or Mk. 2?), they look like a nice car.

Did you see yours and mine old BX A966 XRL had the front cover and a few pages in a classic car magazine recently? I didn’t buy a copy and have forgotten the name of the mag— long story!

I’ve got my C6 in at Pleiades for a sphere regas; they can do C5 saucer sphere too. They are built without the top recharge point but Pleiades add them. Just incase you fancy a cheaper option than replacing all the sphere.
Hiya James, I didn't spot the BX but it is quite a nice one now that Phil had it repainted etc.

Yes, the C5 is an X7 so has two spheres per rear wheel. I think I'll source the two 'soft' spheres alone initially because they're the only ones that 'seem' slightly off just now. Long term project 😉

The more pressing issue is replacing the LH wiper motor, changing the timing belt and friends and beginning the transmission fluid changing process (that i understand takes 3 months 😄)
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Re: New C5 owner with a few questions already

Post by aerodynamica »

Ha, James I see you still have your 480!
I was partly on the look out for a C6 but I just can't get into cars without proper hatchbacks 😟 but the C6 interior looks divine- I love the centre console and gearstick gate. I hope you get on well with it.

It's funny, even with suspect rear spheres, the C5 rides much better than my Xantia TD VSX that has all new spheres, modified height corrector linkages with rose joints replacing the plastic link and ceramic bearings for the levers, rear arm bearings, post 1999 hydractive regulators, new front arm bushings, drop links, anti roll bar bushings, front wheel bearings, ball joints... the LOT! So, what can I say!
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Re: New C5 owner with a few questions already

Post by aerodynamica »

Hi all, mini update. I had removed both wiper motors and found the driver side motor had a manufacture date of 2017 and the passenger one 2008, The wipers were inop but actually worked perfectly on first inspection and continued to work for a good 20 mins during the test drive. They then stopped and haven't worked since. Now that the motors are out I cleaned and dried the passenger side motor's board and used contact cleaner and a small wire brush to clean the odd green bit of corrosion on the board. After an overnight dry I cleaned the sealing surfaces and resealed the unit with normal gasket sealant. Same with the plastic cover on the other side and chacked the little drain hole was clear. I refitted it to the car (the RHS motor was already refitted after concentrating on the LHS one) and after restarting the wipers worked! once... After a bit of time though they worked again for a full 15 minutes..
The problem persists but it seems that the motors themselves are completely fine and that some kind of signal or other isn't working.

I didn't realise the LHS motor was absolutely UNOBTAIIUM though.. Citroen parts dept say it's on like 5 month back order and AEP Citroen in Rutherglen say a similar story (apparently there are 9 orders waiting for 6+ months). I can find no used items either.

I'm playing catch up now - not sure what to do. Probably go ahead with the cambelt change and whatever is knocking on the front right side.

Still, the short trips in the car have been lovely :D
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Re: New C5 owner with a few questions already

Post by aerodynamica »

Does anyone know (Marc?) what might allow it to work perfectly for 15 mins and then not respond at all despite restarting and 20 min pause etc?

I think next I'll investigate the driver side motor despite its seemingly recent build date. I might also get the lexia back on it because first time is couldn't communicate with the wipers and I read someone on here say that was a sign of a dead board. Maybe It'll talk now... prob not ha.

Would there be any benefit in performing the BSI reset? I'm not overly sure what this process is for apart from refitting a battery so could be pointless idea.

Also as an aside, when the lexia states a fault is a 'permanent fault' E.g with the rear height sensor, but it still seems to work?
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Re: New C5 owner with a few questions already

Post by GiveMeABreak »

These units are a 'team'. You have a master controlling wiper ECU and the slave wiper ECU in the other arm. Obviously they have to talk together or they will de-synchronise and will collide with each other.

The issue is not knowing which is the faulty one and it is not always the obvious unit. I had mine done years ago under warranty when they started acting erratically - one arm would remain up, then the other would operate randomly, then the other would do the same. Then they would work again for a while and then not at all.

I know some people like yourself have tried to clean these up, but in most cases they may work for a while before playing up again.

As for the height sensor: Be careful here and don't be tempted to lower or raise the suspension manually if there is a fault with the sensor. Doing so can exacerbate any issue and can leave the vehicle permanently stuck in the low position making it impossible to drive if it is faulty.

The height corrector sensors are potentiometers that use simple analogue non-multiplexed data which is sent to the suspension ECU in the BHI. It may just be some sticking of the angular pick up which a bit of silicon oil spray may help. Please don't ever get underneath the vehicle without it being independently supported - as incorrect height data can cause the suspension ECU to make an adjustment even without the engine running which can cause it to drop rapidly and crush you.
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Re: New C5 owner with a few questions already

Post by aerodynamica »

Thanks Marc - forewarned!

Thanks, I'm slowly learning to speak C5 :D

The only detail to add is that the wipers don't go out of sync, they only seem to work fine or just don't work equally.

I'll have a look at the RHS motor now and see what's what.

If you got yours changed under warranty years ago and they're working fine ever since that suggests hope!
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Re: New C5 owner with a few questions already

Post by GiveMeABreak »

Yes, no issues at all once the faulty one was replaced.
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Re: New C5 owner with a few questions already

Post by aerodynamica »

Good to know. I wonder if there was an improvement to the water proofing after a time.
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Re: New C5 owner with a few questions already

Post by aerodynamica »

I would like to change the LDS fluid. I didn't spot it right away but after watching some YT vids about LDS etc I notice the stuff is orange and not the red that I see in mine. I think someone has put PAS fluid in there instead :(

Is there a procedure for draining down the full amount? I see the lexia can do a 'depressurise' that looks like a state of returning as much as possible back to the tank. How is the tank emptied? I can only find videos that show C5 Mk1 where there seems to be a drain hose behind the wheel liner and under the BHI, maybe it's the PAS feed that was used in the vid. Is this the same for the X7? Actually was the BHI changed for the X7 or is it the same unit carried on? If so it looks fairly easy to remove the tank and I read somewhere here the pump might need help to prime.