C5 won’t raise all the way up to the highest level.

[French_Cars]

I have recently purchased a C5 x7 2.0hdi 2010.
The hydraulic suspension go up and down ok apart from when I press the button to the highest level 4th level.

If the height is in normal and I press the up button, the pump kicks in and I can see the car rise from the back and the front. If I press the up button again, the pumps kicks in and the back rises a bit, the front suspension doesn’t move (the pumps keeps going for about 40 seconds) and the display says “maximum height achieved” or something like that.

I noticed that the front height doesn’t change as I was planing a service and couldn’t get good clearance to drive onto the ramps.

1- is the hydraulic pump on it’s way?

I have also been lucky enough to pull up the oil dip stick without the bottom end. I am assuming it has broken and fell into the oil sump. Can’t check oil level as there is no dip stick end

2- is this an issue if stays in the sump?

I would really appreciated it if someone can offer any assistance.

[GiveMeABreak]

As for the dipstick, use the oil gauge on the car dashboard. No it won’t do any harm left there and yes on the DW10CTED4 engine they are notorious for breaking off.

As for the suspension height, there is the possibility that one of the height correctors is faulty, probably the from one has corroded from water ingress. Dont ever get under the car relying on the suspension alone, keep,it supported by other means as if the height corrector is faulty it has been known for the suspension to drop rapidly!

[French_Cars]

Thank you Marc for your reply.

How do I access the oil guard on the instrument cluster. There is only one message which says oil level correct, but it could be overfilled.

-Suspensions:
How do I check level correctors and are they visible/accessesible from under the car? How do they look like?

[GiveMeABreak]

Sorry a typo! I have swapped keyboards and the keys are all over the shop - should of read gauge

As a temporary measure and until you can get a spare dip stick (Part number: 1174G9) these are the indications of the Oil gauge.

"L" Correct oil level "M" Fluid level: Incorrect "N" Fluid level: Not valid

As for the height correctors: be very careful not to disturb these by turning them or moving them - they are set at a specific angle on the rear anti roll bar and on the front - rotating these will cause the height references to become out of kilter.

Make sure there is a little grease on the areas I have marked in Red and then work the suspension up and down a few times. (but not while you are under it obviously).

Front Height Corrector	Rear Height Corrector

[myglaren]

If greasing and exercising it doesn't work then, with the car firmly supported on ramps/axle stands etc. then try unplugging the sensor ( just a posh potentiometer), cleaning the contacts and spraying with Servisol or Isopropanol, work the plug in and out a few times too to help remove any corrosion and make a good contact.

If that fails it will probably need a replacement sensor, about £30 from the dealer.
I have a vague recollection that someone dismantled and cleaned one that then worked OK - no idea how long for but they have been found with burned-out tracks so beyond repair.

[Hell Razor5543]

I remember somebody opening up a height controller and found that, while the PCB had round holes, the connector used square pins, and solder was distinctly lacking. Once they did a better job of soldering (and re-sealing the cover) the sensor worked properly.

[French_Cars]

Great info thank you all.

Would a faulty sensor trigger a DTC’s if not working properly? I have scanned the suspension unit for fault codes and the only one I have is invalid vehicle speed received from CAN.

[GiveMeABreak]

That’s from the ESP ECU and is normal for it to return that code when the ESP ECU is queried in diagnostic mode.

The sensors themselves do not have any diagnostic codes as they do not contain any ECUs. They just send the relevant positional information to the Suspension ECU. If the tracks are bad, just replace the sensor, it’s really not worth the hassle of repairing these IMHO.

They do get corroded over time due to their exposure to the elements. If you are going to replace it, make sure you mark the position of the original before removing it otherwise you will have to reprogramme the vehicle heights.

[French_Cars]

The ABS/ESP ECU should broadcast the speed of the vehicle into the CAN bus. ABS is not reporting any DTCs (there are no lost coms with ABS in BSI or Powertrain ECUs) that’s why I was not sure to why the suspension was reporting this error.
I will do another scan as I cleared all the faults and see if it comes back.

Height sensors should communicate their position to the suspension unit. If the desired height/level was achieved, the suspension units stops motor as a result.

I think in my case, the desired height was not achieved but the motor times out as it was running for a 1 min or so.

My question, if the suspension ECU has requested a height but has not reached it, surely it should flag a DTC?

[GiveMeABreak]

It will come back as this is a well known issue acknowledged by Citroen, a ghost fault if you like. There is nothing wrong with it when it appears, unless there is another fault with it and this error will appear every time you run a Global Test or the ABS / ESP ECU is interrogated. Ignore it.

As for the suspension issue, there are many fault codes, and back up modes that are initiated depending on the fault. In this case the data being sent is sufficient for the vehicle to operate in normal mode or not severe enough to trigger a specific fault. If the height correction data was well out or not within acceptable parameters, the suspension ECU would probably throw a fault code and the BHI would enter a backup mode and prevent any further height correction to save the pump motor.

For the 4 cylinder engines, have a look here if you want to see the relevant data sent:

viewtopic.php?f=3&t=60610&hilit=Height+ ... or#p582321

[EDC5]

I Had this issue a while ago and whilst I accept that the height correcter needs replacing, doing so on the X7 requires the front sub frame to be dropped according to the official procedure... so that's not going to happen

My solution was to move the clamp on the ARB so the car sits a bit lower. Now it can reach all of the set points from low to max height.

[mmatin]

Hey Mark, as for the oil dipstick, can it be placed into the spot without first removing bottom end of the broken one?

[GiveMeABreak]

Yes, the broken bit will stay at the bottom where the gauze or mesh will stop it going anywhere it shouldn’t. Citroen used to remove the sump cover to remove it, on these, but because they kept breaking off, they stopped doing it!

I’m not sure if they changed the design , but there was a replacement part for these.

[mmatin]

Ok, thanks Marc