I'm wondering if anyone can tell me what creates the figures you see when calibrating the suspension with a tool such as the IID? We are told the figures you see are not really relative to the physical height of the car. Is the number generated from the height sensor unit or from a suspension module or a calculation derived from a number of factors?
The reason I'm asking as some will know I have had a long standing problem with a list on the NSR. Everything is straight, nothing leaks, replaced the height sensors, replaced the Yaw sensor, serviced the valve blocks.
When my local Indy looked at it on his equipment the car shows a big difference in calibration figures between the NSR & OSF. We can get the vehicle to look physically level but in doing this creates a differential in the values greater than 20. This means that anything over 30MPH & she throws a fit, dropping the suspension with dash warnings.
We have got to a 10mm physical difference between heights across the rear axle & the car is happy, but it is still leaning!
I want to get to the bottom of whats generating this big tolerance between the heights on the corners of the car or at least narrow down the options to try & solve it with the help of my indy once & for all.
Any thoughts?
Cheers n Gone Nick MY16 D4 Landmark SDV6 (The Ice Maiden)
Uncle Ray's spare wheel protector
MY08 D3 HSE Stornoway (Miss Moneypit) The money tree withered......
21st Dec 2019 5:45 pm
aja4x4
Member Since: 14 Apr 2019
Location: Westbury
Posts: 2459
The sensors give a resistance value that the ecu converts into approximate mm values.
The mounting position of the sensors close to the pivot point means that 1mm movement at the sensor could workout as 10mm difference at the wheel arch.
How many sensors were replaced, it could be the resistance values change as the sensors get older which can be calibrated out.
It could also be resistance in a connector throwing the values out.
21st Dec 2019 5:59 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4658
The values you see on your IID are arbitrary and are not relevant to the "actual" height you are calibrating. However, the "increment" you are inputting is reflected in actual height change!! So if you increase an "arbitrary" value by 15mm the increment/height is altered by that amount.
Afaik the calibration is calculated by the control module based on the input values and the height sensor.
I'm just wondering if your list is not being influenced by other factors such as suspension bushes. The car needs to be empty of any excess weight and have a full fuel tank, but this I'm sure you already know.yµ (idµ - eAµ) ψ=mψ
The sensors give a resistance value that the ecu converts into approximate mm values.
The mounting position of the sensors close to the pivot point means that 1mm movement at the sensor could workout as 10mm difference at the wheel arch.
How many sensors were replaced, it could be the resistance values change as the sensors get older which can be calibrated out.
It could also be resistance in a connector throwing the values out.
All the sensors were replaced at the same time with genuine Land Rover parts. Might be worth investigating the to see if this is affecting the resistance value.....
Cheers n Gone Nick MY16 D4 Landmark SDV6 (The Ice Maiden)
Uncle Ray's spare wheel protector
MY08 D3 HSE Stornoway (Miss Moneypit) The money tree withered......
The values you see on your IID are arbitrary and are not relevant to the "actual" height you are calibrating. However, the "increment" you are inputting is reflected in actual height change!! So if you increase an "arbitrary" value by 15mm the increment/height is altered by that amount.
Afaik the calibration is calculated by the control module based on the input values and the height sensor.
I'm just wondering if your list is not being influenced by other factors such as suspension bushes. The car needs to be empty of any excess weight and have a full fuel tank, but this I'm sure you already know.
Hi, this problem first showed itself "suddenly" a couple of years back. Long story short the LR dealer managed to re calibrate it after many failed attempts by me with the IID. I'd forgotten about it until the other day when the problem started to reappear, although not as badly. She had new rear upper arms & bushed both sides last year, always empty with around 2/3 of a tank of fuel. On the indy's equipment which i think was Autologic you could see the figures for the NSF & OSR were wildly different with one being in the negative & the other in the positive. I forget exactly what the numbers were.
My thoughts are presuming the height sensors are good that there must be a wiring issue somewhere chaffing etc that could be causing issue. I'd inspected the under the wheel arch on the NSF last winter & found nothing & have had the rear valve block & wiring apart a number of times too. Though I've not taken much notice of the OSF. Is there anything there that is a known weak point? It's only sisnce the indy pointed out the differences in the opposite corners that the OSF has come into play as a possible cause of the problem
Cheers n Gone Nick MY16 D4 Landmark SDV6 (The Ice Maiden)
Uncle Ray's spare wheel protector
MY08 D3 HSE Stornoway (Miss Moneypit) The money tree withered......
21st Dec 2019 6:50 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4658
Did you try calibrating using the "Guided Calibration" in IID? You could have a look in live values and see if there's anything obvious or unusual going on. Beyond that and without supporting dtc's its going to be trial and error / guesswork which is never ideal !
A hard reset might be worth a shot!yµ (idµ - eAµ) ψ=mψ
I tried both on the IID, I could get the car to look right change heights & all would look good. Drive it a couple of miles & back to square one. It was only the dealer that managed to set it right.
The issue is that to set the car so it is visually right on the ramp using the indys equipment, the tolerance on the values is greater than the car will accept. To get the car to accept the values I end up with this 10mm difference in height across the rear axle.
I'll pop out tomorrow & grab some live values to see if i can show the differences.
Cheers n Gone Nick MY16 D4 Landmark SDV6 (The Ice Maiden)
Uncle Ray's spare wheel protector
MY08 D3 HSE Stornoway (Miss Moneypit) The money tree withered......
21st Dec 2019 7:48 pm
MikeO
Member Since: 15 Jan 2014
Location: The Cotswolds
Posts: 1372
You could measure the resistance of the height sensors over their range of travel. I remember seeing the procedure in the workshop manual.
If you can access the 'other' end of the run (EAS module?) it would allow you to check if there is a wiring fault.2016 Skoda Octavia VRS Estate
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As promised a screen grab of the current calibration for Moneypit at on the drive in standard height.
I've not had chance to check the resistance on the wiring from the sensor to the module (not even sure where that is yet!)
She is visually lower on the NS across the rear axle, not a lot, but noticeable
I presume a bad wire / earth would give greater resistance than a good wire. So, does more resistance equal the car thinking the suspension on that corner higher or lower? This might help me pin point which corner is at fault.
For example if the NSR has a wiring fault & is creating greater resistance than it should would this mean the car thinks that corner is higher than it actual is due to the increased resistance & therefore & therefore when it tries to level it drops the NSR lower than the rest?
I hope that makes sense!
Cheers n Gone Nick MY16 D4 Landmark SDV6 (The Ice Maiden)
Uncle Ray's spare wheel protector
MY08 D3 HSE Stornoway (Miss Moneypit) The money tree withered......
23rd Dec 2019 12:16 pm
M3DPO
Member Since: 22 Sep 2010
Location: Notts.
Posts: 8110
Are you sure the height sensors are in the correct position?- front and rear have different length arms, I don’t know for sure if they can be fitted to the wrong axle.
It is well worth your while to read the full instructions and explanation in the Iid tool manual to help you understand how the system works, 10 mm across the axle is acceptable.It can when others can't,
It will when others won't,
It goes where others don't.
Yes the sensors are on the correct location they changed from being marked with colours to A&B sets if I remember correctly.
I've been over the IID manual many times also with the help of the chap from Gap to calibrate the suspension and I'm aware of the 10 mm tolerance the suspension has before it changes height to prevent the system overworking unnecessarily. However the height discrepancy always reoccurs on the same corner. The IID and Autologic systems cannot calibrate it correctly hence looking for other issues in the car that are throwing the values out.
I'll keep thinking whilst waiting for the next dry day to get under the car. The 25th is looking promising
Cheers n Gone Nick MY16 D4 Landmark SDV6 (The Ice Maiden)
Uncle Ray's spare wheel protector
MY08 D3 HSE Stornoway (Miss Moneypit) The money tree withered......
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