C5 X7 rear suspension fun.

[AJM C5]

Alan, that part (11) is the Anti Roll Bar Leer 5273N4. £169.91 inc. VAT over here.

When you say it's not on your car - it must have come away then as this is standard kit - so wither it's been knocked off or corroded and fallen off!

Not on mine, Marc. Is it electronic, where is the connector, what does that 180 euro unit do. No damage evidence. Perhaps it was dispensed with by a mechanic.. What about the twisting of components? Not good IMO.

.

No point running Lexia again BTW, there is no 'raise rear' on my version and that is where the issue lays, and it showed no faults last time. The rear raises and lowers fine now when manually adjusting the HC.

Take your points about running active ride adjustment, but I have a working car now, allowing me to get on with things.

Thanks for the link.

Thinking about it. Will report back..

AJ

[AJM C5]

And thank you again for your Mega Efforts, I'm now mobile again

[GiveMeABreak]

Ok, so part 11 is just the fixing bracket to the anti roll bar that the pick up lever (bone) then connects to the electronic height corrector. It is standard kit fitted to all hydractive C5 X7s. Without this, there is no connection between the anti roll bar and the electronic height corrector, and without that the suspension ECU will throw a wobbly.

So a very expensive clamp, but essential.

[ActivaV6uk]

Lol hadn't seen Marc's response

Part 11 is the clamp that bolts onto the ARB. If this is missing, then your sensor has no reference point from the suspension. Evey hp Citroen has had this part, if it's missing then your rear sensor is literally in the wind.

That part will be easy to get you just need a scrapped C5 with hp suspension. It's probably worth £10 to a scrap yard. The estate and saloon parts will be the same.

As a warning if that sensor gets hit by something under the car it could make the back jump up or down and if cornering throw you off the road as it will change the handling and possibly drop you to the bump stops (mine are missing because it's dropped at speed one to many times). The part is essential to the suspension as it's how all the feedback at the back of the car is gained, your system must be getting all it's ride height info from the front only, should that fail or the link drop you could also be in trouble.

[AJM C5]

Gents, my C5 has that bracket, believe me, although new to the magicery of Citroen space age engineering (oops let's no go there ), after nearly 40 years of maintaining cars, a dangling connector bone to the HC would have rung an alarm bell in my head. It was my astonishment at the price I was quoted for an as then unidentified component which must surely have been highly technical as to demand such cost, and now disbelief that I know it's for a bracket..

That aside, until I decide what to do about that whole arrangement, I thank you for the words of caution.

AJ

[AJM C5]

Have been driving around for a few days now, no problems. That was with the rear existing Height Corrector disconnected.

Today, I installed a new Cit/P HC and connector bone to the rear. Same problem as before; The rear lowers immediately the car is moved, perhaps over uneven ground... Well, it is uneven, thus sending a signal to the Ecu. (Broke a golden rule there, buying GENUINE parts before properly diagnosing what the problem is. At least I didn't buy the €182... bracket.).

Chatting to a local C5 owner who converted his C5 to spring suspension, he says its Ecu/settings issue.

Just ran DB. Pics below. What I will add though is that the 'Normal Driving Height' on my C5 is clearly at semi-high...

The rear reference setting in DB seems out of kilter with the rest.

Can I reset any of these via DB? If so, what and how.

The Raise Rear Actuator option triggers but does nothing to raise its height.

Just reiterating, the rear now raises and lowers and holds position via manual HC adjustment and/or static setting. And the pump works fine. Connect it via the socket and the rear lowers to the bump stops.

Thanks (Marc).

[GiveMeABreak]

Ok, so I think you have a problem with the rear height correction position of the clamp. Disconnecting it has left it at a default setting or where the ECU thinks the height is. Once you connect it back up the ECU thinks the rear is higher than it is and allows fluid to return back to the tank to lower the vehicle to where it thinks it is.

As I mentioned in an earlier post the adjustment that can be made with Diagbox only allows for a relatively narrow range of adjustment - a fine tune of a few centimetres or so, anything more requires the clamp to be adjusted first. This is normally loosened slightly and adjusted by rotating the clamp in very small amounts one way or the other depending on the lowering or raising, and then allowing the car to adjust.

Obviously you need to support the car whilst adjusting when you re under it, then allowing it to return to the ground to allow the car to adapt. Getting it looking near normal height at the rear visually would be a good start and then proceeding with the height measuring calculations to fine tune would be my advice.

If it helps, I can give you my X7 rear measurements crudely from say the centre of the top the rear wheel arch to the centre of the wheel cap. I do have a Saloon, not the Tourer though. If it helps, let me know and I’ll do the measuring in the morning for you.

I can supply the height correction calculation procedure at the same time for you. The entering in Diagbox is relatively straight forward, the measurements just need taking from certain points and use the formula first. Let me know if this will help Alan.

[AJM C5]

Hi there, thanks for being around..

First a couple of clarifications/corrections:

'Have been driving around for a few days now, no problems. That was with the rear existing Height Corrector disconnected.' : Only the dog bone was disconnected, the HC was statically set, and plugged in to the circuit.

'The Raise Rear Actuator option (in DB) triggers but does nothing to raise its height'. : It does actually raise the rear a couple of centimeters, as does the front one too when selected.

'Just reiterating, the rear now raises and lowers and holds position via manual HC adjustment and/or static setting. And the pump works fine. Connect it via the socket and the rear lowers to the bump stops' ; should read... Connect it via the socket to adjust via the clamp and its fine, but then move the car and the rear lowers to the bump stops.

.

If your first paragraph still applies, I draw your attention to the fact that when the car is set to the normal driving height, it clearly at the front at least, is actually riding at semi-high. And the rear filtering position shown in DB (I said rear reference height before...) appears out of kilter, 189, the front filtering height is lower at 140. What is the filtering height? I know the previous owner had issues with the suspension... the seized Regulator demonstrated that, but I wonder if their garage mechanic has changed the Ecu settings too. Normal height should be lower I'm sure.

Yes, your height settings on your saloon would be useful as would knowing what DB says for these settings if you have the time. Also the correction formula, and how to input and upload via DB.

Otherwise all understood on your reply.

Thanks Marc

[AJM C5]

*** NEWSFLASH ***

Before you go to all that trouble, I just tried something, and the car maintains it's height correctly now, so far in testing.

Okay I thought, you've been told to concentrate on the bracket adjustment setting, which I was doing yesterday anyway without joy. So I wondered how it would respond if I set the bracket totally differently to how it was and when I first got the car.

The picture below shows the rear HC and dog bone (plus €182 bracket) when the car is now at normal height as per cab switch. The bracket bolt front is at the bottom horizontal. Before it was up at vertical nearly, facing camera to rear. It moves freely around and with the ARB. When running, and I get in the car it detects weight and now pumps for a couple of seconds (I'm about 13 stone) and maintains height. Manoeuvre car and it now holds its height. Stop engine, get out. Get in and start, pump does 2 second spurt and a quick few manoeuvres and it's all working as it should. Stop engine, get out.... And it's still holding.

I've left it on normal driving height for now.

[Hell Razor5543]

I wonder if, some time in the past, work was done on the rear of the car (such as, maybe, the ARB was replaced) and somebody failed to take note of which way the bracket was mounted. Then, when they put thing back together, they put the bracket on wrong, and it has then affected the suspension. It could well be worth comparing your X7 estate against another one that never had suspension issues. Maybe somebody off this Forum can take a few relevant pictures for you?

[AJM C5]

Hi,

Yes very possible, it doesn't take much to get it wrong, that's for sure.

Although I tried to find photos in the early stages of the work, nothing was definitive. Descriptions however did state that the HC arm and dog bone should be in the dog-leg shape angle pointing to the ground, which it is now, but not so dissimilar to before. It's hard to say how this set-up works and the others didn't for my car, but think that the sensor arm angle AND the pivot position on the bracket is very important in conjunction to movement of the car which was where it was failing. The HC design and Ecu set-up are clearly highly dependent on being fed logical and system consistent information, and even though the HC is only an analogue potentiometer, unless it obeys the Ecu rules it goes haywire... or responds... 'Computer says no!'.

Anyhow, Le Grande Fete is on in town later today, and it looks like celebration time!

Cheers.

[Hell Razor5543]

I cannot speak for the X7 H/C, but the ones for the C6 and earlier C5 were not a carbon track but a whole series of little contacts, arranged (I think) in three concentric arcs. The problem with them was the lack of solder, trying to hold square pins in round holes. The pictures I saw on this Forum (they are no longer there) showed gaping cavities around the pins prior to being worked on, and a proper amount of solder securing the pins afterwards.

[GiveMeABreak]

*** NEWSFLASH ***

Before you go to all that trouble, I just tried something, and the car maintains it's height correctly now, so far in testing.

Okay I thought, you've been told to concentrate on the bracket adjustment setting, which I was doing yesterday anyway without joy. So I wondered how it would respond if I set the bracket totally differently to how it was and when I first got the car.

The picture below shows the rear HC and dog bone (plus €182 bracket) when the car is now at normal height as per cab switch. The bracket bolt front is at the bottom horizontal. Before it was up at vertical nearly, facing camera to rear. It moves freely around and with the ARB. When running, and I get in the car it detects weight and now pumps for a couple of seconds (I'm about 13 stone) and maintains height. Manoeuvre car and it now holds its height. Stop engine, get out. Get in and start, pump does 2 second spurt and a quick few manoeuvres and it's all working as it should. Stop engine, get out.... And it's still holding.

I've left it on normal driving height for now.

IMG_20190802_101533.jpg
IMG_20190802_101603.jpg

I think I've posted this elsewhere but here's a picture of the position of the components for the rear height corrector and clamp for information:

Height correction procedure follows shortly...

[GiveMeABreak]

So here's the height correction procedure to be used with Diagbox for when you need to fine tune it Alan. Be aware that the units shown in your Diagbox screenshots are 'Steps' not units of measurement....

Procedure: As always, never get under the car when undertaking any work on the suspension system unless it is fully supported - especially so when adjusting height correctors (danger of crushing).

1 Tools

A Diagnostic Tool (Diagbox)

2 Preliminary operations

• Verify the tyre pressure.
• Place the vehicle on a 4-post lift.
• Slacken the parking brake .
• Position the body height at the high position.
• Position the body height at the normal position (driving height).
• Switch on the ignition.
• Raise the vehicle.

Identification: Measuring zones - Vehicle heights at setting height

Wheel radiuses R:

• R1: Front wheel radius (L.H. side)
• R1': Front wheel radius (right)
• R2: Rear wheel radius (L.H. side)
• R2: Rear wheel radius (right)

Heights H:

• H1: Height between the measuring zone under the front LH subframe and the ground
• H1': Height between the measuring zone under the front RH subframe and the ground
• H2: Height between the measuring zone under the rear LH axle crossmember and the ground
• H2: Height between the measuring zone under the rear RH axle crossmember and the ground

Heights K:

• K1: Height between the wheel centre line and the measuring zone under the subframe (left hand front)
• K1': Height between the wheel centre line and the measuring zone under the subframe (Front RH)
• K2: Height between the wheel centre line and the measuring zone under the axle crossmember (rear left hand side)
• K2': Height between the wheel centre line and the measuring zone under the axle crossmember (Rear right hand side)

"Z1" : Measuring zone under the front subframe.
"Z2" : Measuring zone under the rear axle crossmember.

3.1 Check: Front height
Measure:

• The wheel radiuses R1 and R1 ; Using the tools [U701-0], [9801-T]
• The heights H1 and H1’ ; Using tool [U701-0]

Calculate:

• The height K = R1 - H1
• The height K1' = R1' - H1'

Calculate the average of the heights K1 and K1' : (K1 + K1') / 2.
Compare this calculated height with the reference height.

N.B.: Reference height (front) : 160 ± 6 mm.
Pre-adjust the front height if (K1 + K1')/2 is greater than 190 mm or less than 130 mm (Section 4).

3.2 Check: Rear height

Measure:

• The radiuses R2 and R2’ ; Using the tools [U701-0], [9801-T]
• The heights H2 and H2’ ; Using tool [U701-0]

Calculate:

• The height K2 = R2 - H2
• The height K2' = R2' - H2'

Calculate the average of the heights K2 and K2' : (K2 + K2') / 2.
Compare this calculated height with the reference height.
N.B.: Reference height (rear): 106 ± 6 mm.
Pre-adjust the rear height if (K2 + K2')/2 is greater than 140 mm or less than 80 mm (Section 4)

4 Pre-setting the heights
4.1. Pre-adjusting the front height

Slacken the fixing bolt (2).
Slightly rotate the collar (1) on the anti-roll bar.
Wait for the correction of the vehicle’s height.
Re-tighten : The securing bolt (2) ; Tighten to 0,6 daN.m.
Do a new check of the front height :

• If (K1 + K1')/2 is greater than 190 mm
• If (K1 + K1')/2 is less than 130 mm

4.2. Pre-adjusting the rear height

Slacken the fixing bolt (4).
Slightly rotate the collar (3) on the anti-roll bar.
Wait for the correction of the vehicle’s height.
Re-tighten: The securing bolt (4) ; Tighten to 0,6 daN.m.
Do a new check of the rear height:

• If (K2 + K2')/2 is greater than 140 mm
• If (K2 + K2')/ 2 is less than 80 mm

5. Adjusting the heights; Using the diagnostic equipment
Connect the diagnostic equipment to the vehicle’s diagnostic socket.
Carry out an global test.
Select the corresponding "suspension" menu.
Select: "SUSPENSION".
Select: "Adjustment of the vehicle reference heights".
Follow the instructions on the screen.
Calculate:

• 320 - (K1 + K1')/2 (for the front)
• 212 - (K2 + K2')/2 (for the rear)

Enter these values into the diagnostic tool.
Wait for the correction of the vehicle’s height.
Check the reference heights.

[AJM C5]

Wow.

Okay, my bracket is now set just a bit more to the horizontal than your graphic and it works, whereas before, the bolthead was opposite..IOW where the end threads of your graphic bolt is. Thus the pivot position and HC arm couldn't have been correct, or maybe were once or twice as per a stopped clock.

Great work on the pre and fine tuning there Marc, quite a lot to it... but I won't be daunted.

If you were at the Town Fete here tonight I could buy you a

Thank you very much.

Cheers