pcourtney wrote:

I guess the likelihood for a height sensor to fail is pretty high on these L322's

so shall I just replace all 4 height sensors at the same time, given that my 2011 was 11 years old last week

NB I also can't figure out how to do live readings on my IID - so maybe overkill, but probably best to replace all 4 sensors !

GraemeS wrote:

Phoenix wrote:

. high(er) resistance would usually lead to excess current flow

Quite the opposite - the higher the resistance the lower the current flow.

The assumed extra current due to localised heat is just a transfer of heat generation from the device being powered to the poor connection site. As there is no increase in electrical load for the completed circuit there cannot be an increase in power consumed. A different story if there is a leak from a corroded joint to earth, such as when corrosion on a battery terminal that is leaking to earth through moisture as an additional load is involved.

But in the end, the connector still overheats and the fuse still ruptures.... Semantics I know, it does illustrate that reality doesn't always conform to proven laws of physics.
The assumed extra current is usually measured as such by the fuse - the blown one.

2012 4.4 TDV8 AB

As per this topic the ride has not been as soft as I expected for some time.

Last week - suspension fault, limp mode, max speed 30mph, still managed 40-50mph to the brilliant New Forest Garage Services in Cadnam, Southampton.

Front right ride sensor wasnt working correctly. The compressor was overheating while compensating and probably had been for years.

Replaced front right height sensor
Replaced compressor

The ride is now amazing.



. 2012 L322 4.4 TDV8 AB low mileage - a peach
1986 V8 Defender 90 County ex-Swiss Army - Red everything....

My preferred Independent: Roy Hardy. R & B AUTOS LTD, 20 Brook Road, Wimborne, Dorset, BH21 2BH (Ex LR Chief Technician)

Last edited by Range Rover L322 on 20th Sep 2022 8:53pm. Edited 1 time in total

That’s good news. Ordered height sensor for mine this morning from Duckworths.

 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport

Hi all

Im wondering if my height sensors are faulty and this is causing the harsh ride, I recorded the voltages on the sensors whilst raising and lowering the car on the drive, you would expect a smooth transition through each move but my readings on the Front Left and the Rear Right have some spikes on them.

I wonder if these spikes are whats causing the adaptive dynamics to firm up the suspension?

Are you measuring the suspension height sensors or the adaptive dynamics (CVD) height sensors, noting that there are 2 height sensors in each physical device.

Take a look at this…


Pretty much the same symptom re spikes, however his was generating an error. We just experience harshness.

However it’s a good theory it’s causing harshness due to confusing spikes. I thought the same yesterday and drove monitoring the 4 corner voltages. It’s hard to say if the spikes were due to normal bumps, or were occasionally erratic… so intend to diagnose further.

What I did notice was that the road bumps different spikes front / rear. Although it could be due to a heavier front of car causing it to bounce more / less.

Again more investigations needed here…

One thing that I do see and wonder if it’s an issue, is that the voltages are different. My ride height is level, however I am seeing a difference of around 1v

Click image to enlarge

GraemeS wrote:

Are you measuring the suspension height sensors or the adaptive dynamics (CVD) height sensors, noting that there are 2 height sensors in each physical device.

The two sensors are exactly the same for the EAS & ADM, the reason for two is that the extra processing required to broadcast on CAN was too much of an overhead at the time, it was considered better to input the signals directly rather than have potential delays or missing messages on CAN. Obviously things have moved on and L405 works happily with network data.
There is a graph showing the correct range of front, rear, left and right height sensor voltages, the rears are generally as posted above, I'll add the graph to this post later.
In my opinion, it would be a mistake to measure the EAS voltages and assume the same voltage is present at the ADM, the signals are analogue DC so are easy to measure at the ADM, if you don't have any data logging equipment, then a simple plausibility test would be to display the EAS voltage on your diagnostic system and use a voltmeter to measure the signal at the ADM as you change the suspension height. If the voltages agree, then its safe to assume the voltage displayed from EAS will be the same as the voltage at the ADM. Obviously that needs to be done for each height sensor, it would be a good idea to check for any mechanical issues with each sensor as well.

Last edited by Phoenix on 22nd Sep 2022 3:50pm. Edited 1 time in total

GraemeS wrote:

Are you measuring the suspension height sensors or the adaptive dynamics (CVD) height sensors, noting that there are 2 height sensors in each physical device.

I was measuring the Voltage from the height sensor for the suspension via the GAP IID, I don't think we can get the output for the CVD system through the GAP tool, I wasn't aware that the sensor provided two separate outputs.

Do we know of a way of reading the output for the CVD from the height sensor?

Are these the graphs you mean Pheonix?

 2012 TDV8 Autobiography Baltic Blue
Previous
2007 BMW M5 E60

So those graphs suggest the voltage between the two fronts (and applies to the rear) should be the same. My 1v difference would indicate Ann 80mm difference in reported height?

Or am I missing something…. 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

You're reading it wrong - 3.1V on the left (green line) is pretty much bang on standard height (zero line) 1.9V on the right (red line) is also pretty much bang on the zero line.

Thats the graph I was going to post BTW

I think there are misconceptions on the function of adaptive damping, transient signals indicate momentary height transitions, for these, you want soft suspension, not the suspension firming up as soon as a spike begins to form.
changes in the signal that are maintained over a longer period (and we're talking tens of milliseconds and above, not single number periods or a high frequency of transitions both up and down) together with accelerometer input is what will, or should, cause the duty cycle to increase. along with CAN info from brakes and steering angle.

Think of what the inputs should look like if you were flinging it into a left-hand tight bend:-
Front right height sensor mean signal would drop to ~1.5V or lower, rear would drop but by less of a margin
Front left height sensor mean signal would rise to ~3.6 or higher, rear would rise but by less of a margin
Front right accelerometer voltage would rise, front left would drop, rear would barely change.
What should happen is the front right damper stiffens, possible to a >50% duty cycle, front left would possibly stay the same or even drop below 30% (nominally all the dampers operate in the low to mid 30% in a flat road in a straight line with little acceleration) the rears should follow but at a reduced percentage.

Now jam on the brakes - the rear accelerometer will go negative very fast and the rear suspension voltages will go high on the left & low on the right, also very quickly, obviously the front will follow suit, both front accelerometers will rise in voltage and the front dampers should change the duty cycle close to 100% on the right, slightly less on the left, the rears will be stiffer but nothing like the front to enable the airsprings to keep the tyres on as much tarmac as possible for maximum braking.

All the above numbers are pure guesswork, LR and others keep the precise algorithms close to their collective chests but the functionality I'm suggesting above comes from real-world diagnosis & testing across several marques.

It's hard to give accelerometer nominal voltages as it depends upon altitude, last weekend both vehicles were reading 2.03VDC when stationary on all sensors (apart from one that was identified out of tolerance on the subject vehicle) The published tolerance is +/-0.05VDC but the diagnostics were reading (I think) to 8 decimal places, whether that is relevant or not, I have no clue.

Ah, yes now I see that. Thank you for correcting me and giving the very detailed posts  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