ADM height sensors aren't calibrated as their signal is used to detect the rate and extent of change whereas suspenison height sensor signals are used to set the vehicle height so need to be calibrated for normal height. A static signal from an ADM height sensor indicates that the suspension isn't moving but nothing is implied about the suspension height.

colalowe wrote:

So I have been on to GAP and updated my IID tool, I can now see the ADM values which is great!

GraemeS wrote:

ADM height sensors aren't calibrated as their signal is used to detect the rate and extent of change whereas suspenison height sensor signals are used to set the vehicle height so need to be calibrated for normal height. A static signal from an ADM height sensor indicates that the suspension isn't moving but nothing is implied about the suspension height.

Ffrr-lover wrote:

colalowe wrote:

So I have been on to GAP and updated my IID tool, I can now see the ADM values which is great!

Did you need to request a specific version? Or just the latest?
I didn’t have the ability to see these values (or just missed it) and no with the car just now…

I just needed the latest version and they appeared, Pat did advise me to go to the 'ID Tool config' and 'Find ECUs' first and see if they appear after that, mine didn't so I did the update.

all good now  2012 TDV8 Autobiography Baltic Blue
Previous
2007 BMW M5 E60

Phoenix wrote:

colalowe wrote:

So I have been on to GAP and updated my IID tool, I can now see the ADM values which is great!

Although the initial data suggests my sensors on that side are all ok

At the moment stood still all the height sensors are perfectly flat and there's only very minor fluctuations in the accelerometers.

Also it now shows when the current is applied to the dampers so you can see when the system is trying to soften up the damper and when it should be hard. Again initial impression is that the system is working as it should.

Ah well, the new sensors are on the way so ill fit them anyway as the car has done 125000mls so it wont harm to change them.

Recon Ill just have to get used to the ride and stop throwing money at it

It's not just about static values, you need to be looking for anomalies when driving, both from the height sensors and accelerometers, also look at the duty cycles of the dampers - there may be 'hidden' data on CAN having an effect - I haven't a clue what that may be, I'd guess that steering angle and brake activation would / should have some bearing on the duty cycles of the dampers.

It'd be interesting to see comparative values from the same stretch of road with your height sensors as-is, with them recalibrated, and with new height sensors if you fit them - the duty cycle outputs would give you a 'composite' measurement, but you'd need to be on a test route where you can do the same speed, the same line on the road and at least one each of a left and right bend. It would, to my mind, confirm or deny that the control system is operating consistently.

One thing that I have been wondering about, is how the ADM recognises that the suspension is at calibrated height, given the range of voltages that each sensor can output (anywhere between the dashed lines for a given height from the graphs above), maybe the EAS signals the ADM once the calibrated height is stored? Obviously the 'normal' height reference voltage needs to be known by the ADM so it can detect a change, not just a rate of change and longevity of the change.

I will do a test on a road that has some speed bumps and turns on it before I change the sensors and then Ill do the same again with the new sensors as thats a good idea and may be helpful for others

My theory on how the ADM recognises the calibrated height - an its just a theory - is that the calibration mode for the adaptive damping takes its reading from these sensors when you run the calibration for Adaptive damping, I could be completely wrong though and im sure someone with a better understanding will correct me on this. 2012 TDV8 Autobiography Baltic Blue
Previous
2007 BMW M5 E60

Adaptive damping doesn't use its height sensors for vehicle height information, only for suspension movement. They don't need to be calibrated as a static value is what is required to detect that the suspension isn't moving whereas the suspensnion ecu needs to know when the corner is at normal height so needs to be told (calibrated) beforehand.

So, I have fitted four new height sensors.

The rear two both had seized pivots where they join the suspension arm and one of the fronts had stiff parts when articulating it.

With the new sensors fitted and calibrated (I also ran the Adaptive suspension calibration aswell) the ride is better although I can still feel the rumbles on the surface and where the tarmac has a section missing, the thud as it goes over them is not as severe now.

Without going in another 2012 ffrr over the same stretch of road I cannot say if the ride is how it should be now but it is definitely improved, I'm not as conscious of the road surface during a drive now like I was before.

I would definitely advise checking the sensors if you have issues, its fairly easy to check the moving parts, you just disconnect it from the suspension arm, on mine it was the pivot connecting to the suspension that was seized.

The only issue I had changing the sensors was with the small bolts that hold the sensor in place, these go into a sleeve in the plastic housing of the sensor, when I tried to undo them the sleeve just turned within the plastic housing so, I ended up having to cut the heads off the bolts to get the old sensors out.
If I hadn't need to cut off the old bolts it would have been a 10min job each corner. 2012 TDV8 Autobiography Baltic Blue
Previous
2007 BMW M5 E60

Last edited by colalowe on 3rd Oct 2022 3:44pm. Edited 1 time in total

Thats good news!
I had planned to take a look at mine this weekend but then life got in the way and I became Dads taxi for most of the weekend.
Hopefully one for this coming weekend.

If just the connection to arm then hopefully it/they can be freed up. If the unit isn’t smooth then we know if it§they need to be replaced.

I’ll also be disconnecting the sensors and ensuring all connectors are cleaned. Given they are constantly being hit by water and dirt, i want to ensure they haven’t suffered. This might not be an issue at all… but for the sake of a little effort…

It would be good to compare ride quality with other cars too as we do not know what “normal” is on these cars. Opinions on ride quality can vary based on what people expect… Currently driving: 2012 L322 SE Overfinch 4.4 tdv8

Past rides:
2014 Audi Q7 3.0d (good riddance)
2010 L322 Autobiography 5.0 Supercharged
2011 L320 HSE 3.0 sdv6
2014 Jaguar XF-RS 5.0 supercharged
2007 BMW 535D
2005 Mini Cooper S

https://www.fullfatrr.com/forum/topic59478.html

This was the part on mine that was seized, I had a look at freeing it up and it freed up ok with some gentle persuasion, the collar is rubber so pops off easily when freed off, once cleaned up the bolt wasn't round and it was a very loose fit when re-assembled

Click image to enlarge

It would be a good idea to put something like Calcium grease on the spigot to prevent water ingress and provide lubrication. Personally I wouldn't recommend a metal-loaded grease (for much, certainly not for keeping water & muck out). Even if there is no current issues, it will prevent issues further down the line.

@Ffrr-lover - anything with the word 'quality' is very subjective, even the NVH specialists struggle to get any objective measures to compare against. I would add that the biggest single issue I've seen cause 'handling quality' issues are tyres - pressure, wear, (and by association, geometry) correct size (also wheels) and manufacturer. Sometimes to 'prove' the cause, we've had to swap complete wheel & tyre sets from sales cars.
They were such an issue for Citroen that they sent an open letter to all owners of a particular model stating that the tyres fitted as OE are the only ones to be used, if anything else was fitted then any complaints for NVH would not be entertained. I'm sure there are some that will think 'huh, typical Citroen!' but pretty much all vehicle manufacturers have their tyres specifically made and marked as such, for just that reason. Some people think it is just marketing, which I'm sure some of it is, but there are genuine engineering reasons - and differences in the LR marked tyres to the generic ones of the same manufacturer, size and specification.

Just had front upper and lower arms and rear toe arms replaced and a 4 wheel hunter alignment. The car feels 'tighter' in handling terms but the ride is definitely a bit harsher. 2012 TDV8 Vogue (L322)

colalowe wrote:

This was the part on mine that was seized, I had a look at freeing it up and it freed up ok with some gentle persuasion, the collar is rubber so pops off easily when freed off, once cleaned up the bolt wasn't round and it was a very loose fit when re-assembled

Phoenix wrote:

@Ffrr-lover - anything with the word 'quality' is very subjective, even the NVH specialists struggle to get any objective measures to compare against. I would add that the biggest single issue I've seen cause 'handling quality' issues are tyres - pressure, wear, (and by association, geometry) correct size (also wheels) and manufacturer. Sometimes to 'prove' the cause, we've had to swap complete wheel & tyre sets from sales cars.

I don't think the tyre swap will make any difference, I sold my 22" rims to a VW Transporter chap, and went back to stock 20" alloy rims, and with the stock Pirelli Scorpion Zero 255/50/R20 tyres, all in an effort to get back to a stock car as much as I could - all this was in an effort to get back to a more receptive and compliant suspension, instead of feeling all the bumps and potholes in these pathetic UK roads we now drive on

sadly, nothing has changed, my comfort and ride is still the same with the 20" wheels, I can say that it is still worse than my old 2004 L322, and my 2009 L322, I sold the 2009 to get the 2011 TDV8 4.4 Diesel 8 speed auto - don't regret it, cracking car but something odd about the suspension that I can't put my finger on, had all 4 wheels balanced, has 4 wheel alignment done on the Kwik Fit Hunter Hawkeye, all perfect





and yet my suspension does not soak up the bumps like my other cars did, and not as well as my brothers TDV8, or other Range Rovers I have been in lately, have been reading this thread with interest, but it does not look like anyone has come up with a good fix or reason for why this is affecting a good few of us on this forum

Last edited by pcourtney on 11th Oct 2022 2:50pm. Edited 1 time in total

I'm assuming that in a steady state of driving in a straight line the shock absorbers should go to their softest setting and only stiffen up to control roll in corners? Or have I / we got this wrong and they are firm most of the time to anticipate any driver steering input and make the handling feel tight and responsive and only soften when they sense undulating ground but simple things like cracks in the road or potholes just have to be driven over at a stiff setting as there is no way of reacting to these fast enough and no way of the car knowing if it's driven over just one crack or about to drive over 100's 2012 TDV8 Vogue (L322)