C5 serious suspension fault

[Harlequin]

Took my 2002 C5 exclusive estate for its MOT today and it came up with `serious suspension fault`.

naturally it couldn`t be MOT`d







not happy bunny at all! what could it be?

[GiveMeABreak]

Simplest things first - get it supported with stands or on a ramp (undo the LDS cap first if leaving wheels hanging) - don't get under it without support. Give the height correctors a good spray with some silicone grease - they can seize up. Although these are electrical inside - the linkage is still mechanical and road crud can get on these and prevent them from moving properly. I have had the same issue on mine. The dealer lubricated it and did some citrobics and that settled it down. Try this first on both the correctors and see if that makes any difference. Next I would check out the area where the BHI is and see if there is any oil or contamination about that could be playing up with the electronics there. The ECU is on the BHI, so something is interfering with the signals. One dodgy height corrector is enough to upset the system.

[Harlequin]

do you have a photo of the location of them? happy to get in the cold and wet tomorrow !

[GiveMeABreak]

Pop up / PM your VIN Simon - I may be able to find some images, but I'll pop up the diagram for you.

[Harlequin]

VF7**************[VIN obfuscated, can be read by forum staff]

[Harlequin]

also got a perm fault for fuel cap sensor as well - grrr will that mean the dpx pump wont fire?

[Stickyfinger]

yes. The sensor if accessed via the wheel arch and is up by the filler cap , the wires run down and past the fuel tank.

Has the filler cap been replaced ?

[Harlequin]

no , should I? read the magnets might lose strength? its a black `permanent` fault so I cant seem to even erase it

assume the DPX42 wont be injected with the fault?

got a video re suspension height sensor - seems I can use ramps to get under it and spray the linkage?

[GiveMeABreak]

Here's some diagrams Simon: Just son't undo the clamps off the axle as this will muck up the heights further - you just need to ensure you give it a good lube and then work the suspension high and low a good few times and pray again.

Height Correctors C5 MK I

Front Height Corrector

Rear Height Corrector

[Harlequin]

thank you!

[Stickyfinger]

Mine had rusted at the head and broken.

There is a procedure to get the system injecting again, tank 3/4 full etc. ( I do no have it to hand)
The injecting pump can be tested with the lexia, you can hear it fire when commanded to.

[Harlequin]

got 1/2 tank in the C5 - put £30 in today before its MOT.....

[Harlequin]

I can replacement sensors for £30 each - would that be advisable?

[Harlequin]

thought by getting under it and spraying and forcing it up and down would work

it did

for a day!

I'm looking at replacing the sensors - but the ecu is showing a fault *only*

and its mot is supposed to be today , can I take it in in tip toe mode for him to est *eg does it have to move up and down for the mot?)

[Stickyfinger]

No. BUT, they do jack/hang the car up on the inspection bed....so you have to remove the LDS cap for an MOT !