C5 height sensors

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GiveMeABreak
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Re: C5 height sensors

Post by GiveMeABreak »

5277E1 is the Citroen Part number for the unit that will need configuring - they do not supply pre-configured BHIs where the VIN is specified on order now, which was (Part 5277E2) for you C5. The unconfigured ones are showing available from Citroen, but are a tad under £1500. but there is a new one for £786.82 from Poland:

https://www.ebay.co.uk/itm/Suspension-S ... 2767000364

There are different BHIs for Auto boxes, manual boxes, and different engines and suspension variations - but I can't find any references for those numbers you quoted. I know they have the 96 or 98 numbers, but nothing is coming up on them. If you can find an identical engine and with Auto box:

You have DW10BTED4 engine with FAP, Hydractive 3 Plus with Auto Adjustment suspension and the AM6 gearbox. If you can find one from a donor vehicle with this spec. you should be good to go.
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Re: C5 height sensors

Post by C5 and P2 2-8-2 fan »

Have fitted a replacement BHI from a car of the same year and also an automatic but no joy.
Does anyone know the procedure for re-programming a BHI with lexia (I have the one from Easydiagnostics), is it possible or does it have to be done by a dealer?
I tried to change some parameters but it asked to connect to the internet to download which I don't think is possible.

Obtaining another unit from a breaker with the same number is proving very difficult as is finding a company with the software to rebuild my own original, perhaps owners prefer to hang onto Exclusives as long as possible rather than scrapping.
ManyTIA

Dave
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Re: C5 height sensors

Post by GiveMeABreak »

You won’t be able to download anything. If you attempt it, PSA servers will deactivate your interface. As I mentioned, there are only the configuration options I specified before in my earlier post.

But again, you really do need to confirm whether the pump is operating or not.

If not double check the 40 A fuse again. The pump makes a very distinctive noise. The pumps can fail if LDS has been allowed to flow down the tank and into the pump motor. The oil gets in through the join in the pump case and gets into the motor, mixes with the brush material, causes sludge and then overheats and blows the main fuse.

Supplying the unit with a temporary test direct supply will let you know if the pump is working or not.
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Re: C5 height sensors

Post by C5 and P2 2-8-2 fan »

Hi Marc,
Yes that 's what I thought re the download.

The pump is definitely working, it runs from the lexia activation but the car doesn't rise which it should nor does the front and rear rise activation work either.
While I had the pump off I removed the end plate of the motor, there was a light dusting of carbon which I cleaned up and oiled the bearing bush otherwise the motor was good as new.
Also I refilled and pressurised the lds tank with fresh fluid.

Dave
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Re: C5 height sensors

Post by GiveMeABreak »

Ok, be aware that it can take 5 minutes or more in some cases if the system has been completely depressurised - be patient with it and make sure that pressure is applied into the tank neck whilst the engine is running and try turning the steering slowly lock to lock in case there is a massive air lock in there a few times and see if she starts to rise.
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Re: C5 height sensors

Post by C5 and P2 2-8-2 fan »

Just about running out of ideas so have removed the Bitron relay 250030 from under the scuttle (1704 on the wiring diagram), putting 12v across the small terminals didn't produce any clicking but perhaps it needs to be plugged into the wiring harness.
If the pump runs with lexia I would have thought the relay would be ok but have ordered another from ebay to try.
What I cannot fathom is why the dash display only shows down, no normal or high whichever button is pressed.
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Re: C5 height sensors

Post by lcwin »

Dave have you try using lexia to depressurize the system first before removing pumps and electrical parts? The reason is when you depressurize using lexia the ECU will initialize the height sensors to zero then it will use the height sensor initial position to adjust height according to standard inbuilt travel range. The sensor itself don;t have a reference point for the ECU so if the height sensor is moved it will revert back to the last known setting.
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Re: C5 height sensors

Post by C5 and P2 2-8-2 fan »

Hi Icwin,

That is something to think about, I did depressurize with lexia before I drained the LDS tank to remove the pump.
As the pump doesn't seem to be getting a signal to run I am hoping the relay is the culprit, if not I'm not sure where else to go.
In a previous life we were always told that switches and fuses were the first things to look at when fault finding, a relay is just a switch in reality.

Dave
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Re: C5 height sensors

Post by Gibbo2286 »

You said the pump runs, is that so or have I misread what you've posted?
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Re: C5 height sensors

Post by C5 and P2 2-8-2 fan »

Yes from the lexia activation screen but not otherwise.
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Re: C5 height sensors

Post by C5 and P2 2-8-2 fan »

Just a quick update, have tried pressurising with a bicycle pump and fitted a replacement relay (Under the scuttle) with no result.
As the pump doesn't seem to be getting a signal to run could the BSI be causing the problem?
Looking on ebay there is a BSI with the same number as mine but from a manual car, can this be changed to automatic with lexia and will the keys need reprogramming?
Everything else connected with the BSI seems to work ok wondering if I'm clutching at straws but as the price is reasonable I may just buy it as a reserve.
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Re: C5 height sensors

Post by GiveMeABreak »

No - you can't replace a BSI without replacing the engine ECU and the key transponders.

Here's the specific suspension wiring diagram for you in case it helps with troubleshooting connections.

This is for the C5 MK II with unvariable Power Steering, and with Hydractive 3+ Suspension with Auto Adjustment. This is for your specific C5.

Can you confirm when you try to set the height using the height selector switch (7745) in the car, that the display on the dash corresponds to the raising or lowering position you are trying to set? If the display is not budging, that would suggest an issue with the communication between the switch and the suspension ECU - and why the pump might be operating when setting the height using Lexia but not when using the switch. Lexia will talk directly to the suspension ECU, whereas the switch will rely on a separate connection.

Using the diagrams below, I would check the earthing to the switch shown as MC54 and the other connections - it won't be unknown for a liquid spill to upset the connections here.

Hardware:
7715 : suspension control unit
7739 : central electronic block motor
7748 : rear suspension electrovalve
7747 : front suspension electrovalve
1704 : / relay housing
7702 : front body height sensor /
7703 : rear body height sensor /
7745 : vehicle height selector

Suspension ECU (7715) Wiring

7780 : Electric pump unit motor command
7758 : Rear hydractive solenoid valve + power supply
7755 : rear hydractive electrovalve control
7756 : Front hydractive solenoid valve + power supply
7754 : front hydractive electrovalve control
7726 : Front body height sensor + power supply
7724 : front body height sensor signal
7727 : Front body height sensor - power supply
7728 : Rear body height sensor + power supply
7729 : Rear body height sensor - power supply
9001P : Low Intersystem / Can bus
9000P : High Intersystem / Can bus
B7715 : battery +
9000B : High Intersystem / Can bus
9001B : Low Intersystem / Can bus
6260 : Doors info

Image

Here is the location of relevant components

Image


Here are the actual Wiring Connections

Image
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Re: C5 height sensors

Post by GiveMeABreak »

I've updated the post above since posting - to include some possibly relevant info regarding the switch, so please re-read :-D
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Re: C5 height sensors

Post by C5 and P2 2-8-2 fan »

Many thanks for that Marc, there's a correct bsi on ebay for £45, might have known just changing the unit would be too easy.
If I can't find any fault elsewhere suppose I'll have to bite the bullet and send mine off for diagnosing/repair.

Dave
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Re: C5 height sensors

Post by GiveMeABreak »

I'm doubting the BSI to be honest - but do check the switch connections as I mentioned in the edited post above.