D2 SLS

So my rear suspension has gone on teacakes again. Last time it was after a tyre change when (after having all 4 lifted off the ground at the same time) the rear SLS dropped to the floor and the Disco bumped along like a dog with an itchy bum. It was under warranty from an independent dealer at the time, and he fixed it - I suspect by taking it to a local place with Rovacom or whatever and having it reset. It certainly didn't take long or cost much, or he would have made a much bigger fuss.

This time it started about 100m from home. Cause MAY have been exiting from our drive onto the road, which is a bit of an axle-twister and lets the LHS rear wheel hang down a bit, although it's done it a thousand times before with no trouble. The LHS rear wheel is now fully extended in an upwards direction and the car is virtually undriveable.

I've heard that disconnecting the battery for a while can sometimes make the various ECUs forget their troubles, so I might try that tomorrow. Any ideas how long for? (Yes, I have the radio code.) Any other suggestions before I bite the bullet and book it in?

On a slightly different point, if my guess (above) is correct, that would be two occasions where letting the axle(s) droop and the height sensors go out of limits has caused failure of the suspension. I can't believe that a vehicle intended to be used offroad in fairly adventurous conditions could have suspension that was so easily upset. Is this a design fault, or have I just been unlucky?

Advthanksance :-)

Reply to
Rich
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I don't think you're unlucky - it is a feature! I've heard of it when tyre places jack them up high before too. Tho I'm not sure what causes it in certain circumstances as opposed to others. If a sensor reads out of range (i.e. wheel is 'dangling') the system is supposed to increase the ride height to get the wheel back onto the ground (or at least try to). Maybe problems are caused by a height sensor showing signs of aging, or maybe the system needs re-calibrating on Testbook with the necessary blocks?

If your battery trial doesn't work out, perhaps you can leak some of the air out of the air spring by pulling the air line out of the spring (be careful!!). Jack it up and if you are gentle, you can just pull the air line out a little and let the air out slowly, that might bring the height sensor back in range and make it work again?? Just an idea - I don't know if it will actually work in practice!

Matt

Reply to
Matthew Maddock

Mine recently did that going down the slip road to join the M6 at Warrington. After recovery and taking to dealers (under breakdown insurance cover) the fault was diagnosed as a faulty ride height sensor.

These are attached to the trailing arms with rather flimsy looking bits of plastic, might be worth having a waggle of the leads/ reseat the connectors but do be *very aware* that the computer might through up it's hands and deflate the system. There might be acres of space to reach in with the system up but in itchy bum mode there isn't.

Reply to
Dave Liquorice

On or around Sat, 03 Feb 2007 23:47:20 +0100, Matthew Maddock enlightened us thusly:

FFS, this is supposed to be a vehicle capable of extreme off-road use. WTF is the point in the suspension throwing a wobbler 'cos one wheel gets off the ground or similar?

actually, that's a point, what happens in off-road mode, if it has one?

Reply to
Austin Shackles

If "off-road"mode it raises the suspension - tho I can't remember by how much - 25mm or something like that. If the system thinks that the vehicle has been grounded it automatically raises the ride height further to try and free it. As Dave pointed out, the height sensors are flimsy affairs and prone to going bad and sending erroneous readings to the ECU which isn't clever enough to ignore strange readings and throws a wobbly!

Most LR air suspension problems are air-spring or height sensor related.

Matt

Reply to
Matthew Maddock

Isn't that on the D3 though? My D2 has SLS and I don't think it has any such off road 'modes' for the suspension?

Reply to
Darren Griffin - PocketGPSWorld.Com

Yes it does. It has the "off-road" mode you can select from the button on the dash, and an "extended" mode which is not driver-selectable, but kicks in when the system detects 1. a rear wheel spinning, and 2. suspension fully extended. It then assumes you are grounded and extends the air-sus about another 25mm. It's all in the handbook.

Reply to
Rich

Well, exactly. Those were my thoughts.

It will extend into off-road mode (which brings the RHS up almost level with the LHS[1]), but when you tell it to go back down the LHS stays up.

[1] hard to be precise, as the drive is a little undulating.
Reply to
Rich

Perhaps one of the valves is stuck in the valve block if everything else seems to be working ok? I don't know about the D2 but on the P38 you can jimmy the valves open/closed by jumpering power to the right connections. Easiest way would be to get it into a specialist and have them hook it up to Testbook.

Matt

Reply to
Matthew Maddock

Not sure if it's on all DIIs with SLS but mine has the option to pump up the rear suspension by 2". Look in the group of 6 buttons that contain the fuel cap release button, HDC, hazard lights, heated screen(s) etc. The "off road" button is marked with a profile of the vehicle and an upward pointing arrow at the rear. Can't remember what interlocks there are (doors closed, engine running, etc). It does drop out automatically above a set speed (around 15 to 25mph ISTR).

Reply to
Dave Liquorice

I don't think it will the height sensors are mechanical and attached via a pivoted link to the rear suspension trailing arm. The air bags are just bags full of air, the computer controls the amount of air depending on what the ride height sensors tell it.

Reply to
Dave Liquorice

Sadly, I think that's what will happen. I was just wondering if there was a quicker (i.e. cheap) way!

Reply to
Rich

It's spent the day at the main dealers. I left it there last night, leaning like a drunken navvy, and while I waited for my lift it was groaning and farting away to itself like it was dying. In the morning, so they tell me, it was back to the correct height. They can't find anything wrong, and the SLABS ECU is reporting no faults. I had a long chat with the service manager, and he's telling me that the ECU only stores electrical faults, not mechanical, so all the electrical bits (eg height sensors) must be OK. It narrows down to a sticking valve in the valve block (have a coconut, Matt) and the only answer is to drive it until it does it again and then change the valve block. He even told me how to change it myself, and then told me there was no charge for today's investigation. Happy customer.

Now. Snow. BRING IT ON!!!!!

Reply to
Rich B

Now dragging its arse down the road AGAIN like a dog with piles. Right on the bump stops, no rear suspension at all. No reason - just parked up for an hour and it was like that when I came back. That's the third time in 14 months that it has failed. Next time I am going back to a 2CV. Simple and reliable.

Reply to
Rich B

Does it pump itself back up (properly) when you turn the engine on? It might be a duff height sensor, that was the fault with mine. But that just confused the ECU which just threw up it's hands and deflated everything whilst driving... I'd expect that to show up as an error from the SLABS ECU though, even if intermittent.

If you need to be recovered with a deflated suspension any tow hitch will want to be an inch or so below the level of the tramac. Recovery truck will need a couple of 6' long (at least) 2" thicj boards to put under the rear wheels to get clearnce for the "plough".

Reply to
Dave Liquorice

No - it just sits there like a pudding. No SLABS faults on the last check.

I managed to drive it home (about 6 miles) - my guts were like jelly afterwards, though.

Reply to
Rich B

Any warning lights? I can't remember if the SLS lamp came on when mine gave up.

No surprised mine failed on an entry slip to the M6 backend started bouncing up an down in a most alarming way. I was doing around 50 or

60mph mind, it might have been a bit better behaved at lower speeds.
Reply to
Dave Liquorice

Yes, the yellow piccie of the car with its arse bouncing up and down. This is a change from last time, when it had no warning lights at all. Sitting on the drive at home, I tried the suspension raise/lower button. The chimes went and the SLS light flashed, but nothing happened. After 10 minutes like this, I gave up and went inside for a beer.

OK-ish on smooth surfaces up to about 20mph, but our road is rough and it was like a fairgound ride for the last 3 miles. It was so bad it was literally impossible to talk. It is right down on the bumpstops - top half of the rear tyres are up under the arches.

Land Rover - comedy suspension.

Reply to
Rich B

And possibly an indication that the ECU now knows of a problem... All you have to do now is get it to a test book to have gander. Might be worth reseating the connections to the height sensors, particulary on the side that jacked itself to full height previously.

Reply to
Dave Liquorice

Aye, thanks - I'm away on a business trip for the rest of this week, but I'll have another go when I get back.

Reply to
Rich B

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