c5 fuse box b

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scas
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Re: c5 fuse box b

Post by scas »

thanks GiveMeABreak, but i cannot raise the car to normal height or the highest setting and that seems to be the way to bleed it

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GiveMeABreak
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Re: c5 fuse box b

Post by GiveMeABreak »

Ok, so if you are sure the pump motor is operating (should be easy to hear that), you may have introduced air into the system when you disconnected the LDS tank hose supplying the fluid to the pump.

If the system has depressurised, then you may need to introduce 0.5 Bar of pressure into the tank, whilst the engine is running to get the car to rise - but it can take some minutes to do after it has been depressurised. Whilst it is flat on the floor, try bleeding it anyway by very slowly turning the wheel from lock to lock a few times. This will allow the fluid to circulate and get any air out - but may take a good few attempts.

Hell Razor5543
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Re: c5 fuse box b

Post by Hell Razor5543 »

I cannot personally confirm this will work, but citroenxm has said he was able to pressurise the system by blowing hard into the reservoir. I would imagine he did this by initially setting the suspension to a working height, turning the engine on, and then (sealing his lips around the opening in the tank with the cap removed) blowing hard into the tank.

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Stickyfinger
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Re: c5 fuse box b

Post by Stickyfinger »

that image will be hard to remove from my mind !

Gibbo2286
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Re: c5 fuse box b

Post by Gibbo2286 »

Stickyfinger wrote:
29 Feb 2020, 19:46
that image will be hard to remove from my mind !
And even more difficult to remove the taste from his mouth. :)

Hell Razor5543
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Re: c5 fuse box b

Post by Hell Razor5543 »

I bought (from a scrapyard) an LDS reservoir cap, drilled a hole in it, and fitted a tyre valve. Now all I will have to do (to re-pressurise the system) is to fit this cap, start the engine, set a height, and give a couple of strokes with a bicycle pump.

scas
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Re: c5 fuse box b

Post by scas »

:? so heres where im at, pump works when it should, no bubbles in fluid, i can pressurise the fluid so that the container expands a little -so that should be enough. pump will run forever if i turn on the engine, although i stop it after a few mins and the car is still on the deck.

Gibbo2286
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Re: c5 fuse box b

Post by Gibbo2286 »

Then I'd suggest you take a closer look at the height correctors and especially the connectors to them, are they copper corroded?

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GiveMeABreak
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Re: c5 fuse box b

Post by GiveMeABreak »

I think it extremely unlikely that both the height sensors would of failed to operate at the same time Eric and would of given some indication of prior failure - riding too high or too low at either the font or rear - but for both to go just like that is extremely unlikely.

I'm going back to basics and will be putting some info up shortly on the system so the we can try and look at the likely areas.

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Re: c5 fuse box b

Post by Gibbo2286 »

I was thinking more of electrical back feeds caused by corroded connections etc, I know mine did all sorts of peculiar things when the front HC played up.

scas
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Re: c5 fuse box b

Post by scas »

i shall figure out how to jack her up as either of my jacks wont go under it at this point and have a look at the sensors

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Stickyfinger
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Re: c5 fuse box b

Post by Stickyfinger »

If you reverse it up on a few short planks of wood you should be able to see the rear one....and get the jack under the rear sill lift points...that's how I got access to mine, it had rusted the shaft and the head had completely come off !

C5 and P2 2-8-2 fan
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Re: c5 fuse box b

Post by C5 and P2 2-8-2 fan »

Is the F4 fuse in the engine bay box ok?
If its blown it could be one of the ride height sensors shorting out(Don't ask how I know this :-)).

To get my hydraulic jack under I used the scissor one supplied with the car and axle stands to lift one side and proceeded from there, fairly easy at the rear not so easy at the front.
Last edited by C5 and P2 2-8-2 fan on 03 Mar 2020, 15:37, edited 1 time in total.

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GiveMeABreak
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Re: c5 fuse box b

Post by GiveMeABreak »

Parts of the BHI on a C5 MK II
C5 MK II BHI.PNG
ReferenceDesignation
1Suspension ECU
2Hydraulic valve block
6Hydraulic pump air intake aperture
11Suspension ECU connector
12Electric motor supply connector
13Electric motor control connector
14Electric motor
Integrated BHI
The BHI, a monoblock which cannot be taken apart, is composed of the following components:
  • An electric motor to drive the hydraulic pump
  • A hydraulic pump with 5 axial pistons
  • An anti-pulse accumulator, flow regulator
  • 4 electrovalves: 2 per axle, 1 for inlet (raising the vehicle), 1 for outlet (lowering the vehicle)
  • An electronic suspension ECU
  • 2 anti-sink valves
  • 6 hydraulic fluid filters: upstream and downstream of the electrovalves
  • 1 overpressure valve
Electrical Diagram for C5 MK II Hydractive 3+ (not H3)
C5 MK II H3+ Electrical.PNG
Key:
  • Single arrow: Wire connection
  • Triple arrow: Multiplexed connection
ReferenceDesignation
BSI1Built-in systems interface
ADoor switches. Luggage compartment switch (Estate only)
0004Instrument panel
1320Engine ECU
7020ABS ECU
CV00Steering wheel angle sensor (hydractive 3) integrated in the switch module under the steering wheel
7702Front body height sensor
7703Rear body height sensor
7710Sport mode suspension switch (hydractive 3+)
7715Suspension ECU
7745Vehicle height push button

ConnectionsEmitter of the signalNature of signal
1Request for change of height7745All or nothing
4Vehicle height information7702. 7703Digital
6Hydraulic pump motor functioning status (petrol only)7715CAN
8Status of the openersBSI1Digital
11Request to light height correction fault. Lighting of height warning lampsBSI1COMFORT CAN
12Request for change of height. Request for change to sport mode0004COMFORT CAN
13Ignition switched "+". Request for change of height. Principal brake switchBSI1CAN
14Vehicle speed. Longitudinal acceleration. Distance7020CAN
15Steering wheel speed (vehicle not equipped with ESP)CV00COMFORT CAN
16Steering wheel angle (vehicle not equipped with ESP)CV00Digital
17Engine speed. Starting in progress. Accelerator pedal position1320CAN
18Request to light the height correction fault lamp. Vehicle height information7715CAN
19Information on the status of the doorsAAll or nothing
20Lighting of hydractive 3+ activation warning lamp0004All or nothing
21Request for hydractive 3+ suspension7710All or nothing

So can you confirm that the Suspension switch in the cabin is not in 'Sport' Mode as no height correction takes place when in 'Firm' status.

I would also double check the electric plug sockets to the BHI and make sure you can see the pins - if there is any electrical break then it may affect the operation of the electrovalves internal to the BHI (even though the pump motor is working).

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GiveMeABreak
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Re: c5 fuse box b

Post by GiveMeABreak »

C5 and P2 2-8-2 fan wrote:
03 Mar 2020, 15:27
Is the F4 fuse in the engine bay box ok?
If its blown it could be one of the ride height sensors shorting out(Don't ask how I know this :-)).
F4? That's for the Headlamp washer system in the PSF1 engine Fusebox (if fitted) supposedly...

7702 & 7703 (Front & Rear Height Sensors) are supplied directly by the Suspension ECU. So if there is an electrical problem with the suspension ECU on the BHI - then it is entirely possible this will affect the operation of the electrovalves - which is why I've suggested a close look at the circuit / connectors there. The pump itself is supplied independently.