I wonder why it doesn't report a fault Graeme? If the dampers are powered I'd expect to see 'adaptive dynamics fault'

I'd love to hear the outcome of that one when they get to the bottom of it.

I dont get a normal height only fault no so its not leaking enough to effect fill times on the reservoir but it does take an age to lift to various heights as previously described so needs rectifying.

I will use the iid to graph height sensors during height change from the CHCM and CHCMB tomorrow, good suggestion.

I know someone in Landymansams thread 'help me with the suspension on my famous l322' had this issue and it was found by a diagnostic expert... Phoenix I think it was?

Hi Graeme,

I've done some graphing of the height sensor voltages from the CHCM this morning with the IID tool.

All operations were performed with the vehicle running, gearbox in neutral and handbrake off.

Raising from access to normal height and then back to access.

I did not observe any spikes in the signal from any height sensor, all I noted was the off side rear sensor didn't output a stable voltage when normal height was achieved.

The off side rear oscillates whereas the near side rear does not. The oscillation is only 0.03v however so could this be negligible?

I need to run more tests tonight comparing height sensor operation across the car to see if one sensor is slow etc

Is it worth me testing the sensors by hand and graphing at the same time? (I.e. disconnect the sensor link and sweep it through its range of operation by hand whilst watching the graph in iid)

Thanks!

I wouldn't be moving the arm by hand but perhaps graph that sensor while driving slowly on a smooth surface to see if it is still jumping about. I wouldn't expect the extent of the variation to cause the stiffening of a shock but you might want to graph that shock's and possibly the other side's demanded duty cycle/s to see if there's corresponding shock valve operation.

Okay I'll graph all the sensors whilst driving tonight and also try a comparison with shock duty cycle.

I am sure the jumpy sensor is probably nothing as it's literally only 0.03 v variation in the signal from 2.22v to 2.25v and back again which is quite a small amount.

Am I correct in thinking the L405 only has one output from each height sensor to the CHCM?

Need to have a look at the height sensor connect later to see if it has 3 or 6 wires as confirmation of the above.

Only 1 sensor with the signals shared by both EAS and CVD. The dual sensor was only for L322s fitted with CVDs as an after thought.

I thought as much Graeme, so when in viewing height sensor voltages as reported by CHCM these are the voltages that both the EAS and CVD use?

MarianaWestminster wrote:

the empty passenger seat trembles constantly as I drive.

Yes, EAS & CVD use the same signal/volts.

Mine does unfortunately Stuart. In fact the whole car shakes like a defecating dog at motorway speed and yet my 40 year old Ford doesn't.

You'd have thought the 8 year old luxury suv which was infinitely more expensive when new would be better

Thanks for the confirmation Graeme

I've graphed the height sensor voltages driving on a relatively smooth road at 25mph for 20 seconds.

I can't see any voltage spikes or drops in the signals?

I would definitely get the vibration resolved. It will rapidly accelerate steering and suspension component wear and can adversely affect the shock behaviour, let alone your comfort. The cause could be wheel balance, a bent rim, wheel alignment, loose suspension bushes, worn-out shocks or the transfer case or rear e-diff clutch binding.

Oh believe me I've tried Graeme.

All 4 wheels have been checked for run out visually and by the road force machine, all 4 tyres have been thoroughly checked and road force balanced to be within LR spec including replacement of an almost new tyre as it was outside of spec.

Alignment has been done (was only slightly out on the front toe angle) in tight tolerance mode and not before both myself and the technician doing the the alignment went round together and visually inspected all bushes then checked for play using pry bars Including prying under the wheels suspended off the ramp to simulate shock at the road wheels.

Transfer case had the fluid changed and clutches recalibrated less than 10k miles ago by the previous owner and as far as I know mine doesn't have the rear e diff (no rear end lock logo on the 4x4i screen only the center one)

Don't know if it could be hub, driveshaft or propshaft play.

To me it feels like oscillation caused by the suspensions inability to iron out small bumps in the motorway surface.

In that case it seems like there is at least 1 useless shock. Do you know which corner is causing the vibration? If the rear then remove the bottom shock bolt and see if you can compress the shock. If it can be moved 1 cm by hand without great effort while still attached then it will be useless and the other side might not be much better.

PS The Defender has lots of fault codes, some being comms faults and steering angle sensor data invalid so its no wonder the shocks aren't being controlled. A dealer has agreed to look into its problems.

That's another thing to look into then Graeme, thank you.

When I'm next free I'm going to disconnect each height sensor and check it manually watching the IID graphs just to be sure they are all giving a good signal to the CVD.

It will also allow me to check for any mechanical binding etc (I know another member in the famous l322 thread had this problem and want to be sure)

I did go down the route of replacement shocks on both of the 'bad' l322s I had and it never made any difference to either ride quality or vibration reduction but it is another thing to be checked.

Good work on the defender, I hope the owner has good results with the dealer.

If that was me I'd never be out of the dealers having just spent that kind of money on a car.

Last edited by MarianaWestminster on 5th Nov 2023 11:16pm. Edited 1 time in total

Another quick query...

Looking the voltages and m/s2 values for the 3 accelerometers.

All 3 show the same voltage value (vehicle parked, normal height, engine off)

But the front left sensor value reads less than the other 2, why would this be?

Screenshot from IID:

Click image to enlarge