C5 X7 no power steering

[Kees]

Hai, i make some pictures of my car, only it's a 3.0 petrol.
You can see my CSS, and it's says "suspension variable " not "damping variable " as the C6.
You can also see, that i have a mechanical steering pomp, and don't know if yours is the same, or an electric one?
Maybe it's possible to fill the hose leading to the pomp with LDS, and I also read, that you maybe have to ad 0,5 bar at the LDS tank.
I also see some pictures of a saperate tank for the steering pomp, behind the mud protector at the right front wheel.
So you see i try to thinking about the problem and maybe you have something about this
Greetings,
Kees.

[wurlycorner]

Hi Kees
Thanks for replying and the pics.
Mine's a 3.0 HDi V6 and it's a mechanical power steering pump (like yours) rather than electric.

I was very dubious that it was a problem with the mechanical/hydraulic system and now that I have a fault code, I'm pretty sure I'm right in that.
The electrical control side (controls the amount of assistance provided) of the system is where I'll be focussing my efforts now - but that's difficult without any schematic or component diagrams unfortunately. The engine bay is so cramped/full of stuff on this model, visibility of the systems to try and work it backwards myself, is practically impossible.

Does anyone on here have the correct schematic/system component/wiring loom diagrams please?

I'll probably start with the two connectors that I disturbed while changing the N/S/F lower arm, in case they are anything to do with the system. Normally a poor strategy ('hit and hope') but In lieu of any other useful info to go on at the moment (unless someone comes up trumps with the info requested above ) they're the only thing I can think that was 'touched' between when it worked and when it didn't.

[Kees]

I read something back from your post .
"The only thing I can think of that may be related to the power steering that I disturbed is the two electrical connectors that mount on the bracket bolted to the nearside lower suspension arm rear bracket - is one of them related to a sensor/variable assistance control for the rack? However I didn’t disconnect them, I simply unbolted the bracket from the old arm mount (complete) and bolted back onto the new one."

Did you disconnect the rod between the height sensors and the lower arm before unbolt the lower arm?
Because otherwise it's possible, you overstress them.
But you can see if the data from them is correct by using the diagbox.

[Kees]

Here you can see the data from my car, the difference between some height sensor is, the car was not horizontal.

[wurlycorner]

Yes I disconnected the rod - the suspension is working absolutely fine. No issues with it whatsoever.

[Kees]

This is what the service box tells about air in the system.

Ad 0.5 bar on the LDS tank
Start the engine with the wheels straight forward without attaching the steering wheel.
Wait until the car is stable.
Turn the steering wheel 10 times slowly from left to right.

[the-termin8r]

Still getting to grips with my bootlegged Servicebox, but I think the below schematic is the one you're after (or at least it's the only one I managed to dig up).

0004 is the instrument panel

1524 is the supply cut-off relay

7111 is the variable power steering proportional electrovalve
7715 is the suspension control unit (I'm assuming the regular ECU that appears in all H3+ X7s)
7739 is the central electronic block motor
7747 & 48 are the front and rear suspension electrovalves, respectively
7749 is the luggage compartment height selector
7751-54 are the height sensors
7758 is the variable damping ECU (presumably the one you have complaining)
7769 is the suspension buzzer (no idea what that is)

BB00 is the battery
BFH1 is passenger compartment 1 fuse box 1
BPCB is the battery cable protection unit
BSI 1 is the BSI (go figure)
BCM0 is the multifunction switch block

C001 is the OBD port
CA00 is the ignition switch

PSF 1 is the engine compartment fuse box panel

I'll try and see if I can dig up anything on the error codes, but I don't know if I have that ability (EDIT: Looks like I don't unfortunately, I can only do mechanical and electronic schematics).

[Kees]

You see, that connector 7111 is in the same wire harness as the wire from the height sensor, maybe there is something wrong, sometimes because of the movement and some corrosion there's the reason for your problem.

[wurlycorner]

That's fantastic, thanks Rob.
On it today...

[wurlycorner]

Not hugely relevant I don't think - but component 7749 not identified in that list.

Interestingly, the two plugs I'm referring to that I disturbed, aren't shown in that wiring loom drawing (or on the schematic/wiring diagram). So that suggests they are not related to the this system?
Is that schematic/wiring diagram for a RHD car or a LHD car?

[the-termin8r]

I had to look them up manually, must've missed that one, my bad. 7749 is the luggage compartment height selector.

[wurlycorner]

Thanks very much

[wurlycorner]

Progress made on this today?
Zero - because the (-expletive removed-) thing has either developed a horrendous parasitic drain problem, or the two month old Yuassa battery has completely carped it overnight, or it's not charging properly - or a combination of all three.

Drove it Wednesday night (85 miles, so not a short battery draining trip!) and today it was completely and utterly dead. Not the merest sausage of life.
Was able to unlock it (and once jumped, could central unlock it) but couldn't jump start it using another battery jumped onto the terminals in the engine bay and hence wouldn't come out of economy mode.

So the battery is now out and on charge - will test that once fully charged tomorrow, but I'm out all day so can't make any more progress on it then.

I *hope* the cause of parasitic drain is the bluetooth audio streaming thing that I had rigged up piggy-back powered from the passenger fuse box, audio connected into the aux terminals (one of these). I only installed that a couple of weeks ago and noticed when I used it on Thursday that it was no longer working (phone did not discover it). It's confusing though, because I thought I powered it off an Ign. switched live (that was certainly the intent!). It came off G35 - door lighting and electric mirrors.

[the-termin8r]

Check your positive battery clamp (the one with the red box). Mine came with a clapped out Halfords battery. Last week, I go to leave from work, ignition on, economy mode (nothing new there), gets a single crank and then dies. I try again and can't even get ignition. I have to clamber into the boot from the rear seats to open it manually. I have a quick shake of the battery connections and I don't feel anything odd. Gave it a few mins of just sitting there and it ended up coming back to life. Managed to get home and immediately went to swap batteries between my 2L and 3L. Upon disconnection, I saw that the positive battery clamp had a significant crack / break in it and it wasn't making great contact. I tightened it as best I could and it's been holding up thus far. I ended up ordering one from Lithuania on Ebay (seems to be the only place to find these), it came in broken in exactly the same way. Seems to be a common failure mode for these and they also appear to be rare parts.

[wurlycorner]

Thanks for the tip. Will check when I come to refit it.
Amazingly though, I think it may be the battery!
One of my smart chargers refused to charge it (didn’t even recognise I had anything connected, so refused to turn). The ctek mxs3.8 did start, but when it got to stage 5 it stopped and put on the fault light - never seen that before.
Might be a shorted cell.
I’ve restarted the ctek, see what happens this time and then I’ll test it with my battery tester either way.