On my way back from work stopped at a petrol station. Starting the car again I get HDC inactive / Air Susp. Inactive and the amber warning triangle.
I drove a few meters and I can remember the ABS amber light and the one next to it on as well...

I switched off and on again and the HDC / Air Susp messages as well as the amber warning triangle remain.

I pulled the negative from the battery and allowed a few minutes.

Reconnected and did the lock to lock thing which clears the ABS and the other next to it but HDC and Air Susp warnings came back within seconds.



If I switch off and on again, the sequence of events is as follows:

Front of car will raise a bit

The HDC warning comes on

A very few seconds later the Air Susp warning comes on

Before the Air Susp warning comes on again, you can give a raise / lower command using the knob and the respective led will blink but the operation will never be completed as the warning kicks in and the light on the height adjust inhibitor button comes on.

Then the two warning messages alternate on the dash...

The self-levelling of the car appears to work fine.

Battery is fitted 02/2020. Reads 12.6V and alternator reads 13.8V-14.2V

The compressor seemed to work after switching off on one occasion but cut out soon.

If someone could point me in the right direction based on above, I'd be grateful so that I will be visiting the stealers educated and not with my pants down + lubricant...

Thank you in advance

Last edited by vs322 on 18th Aug 2021 9:14pm. Edited 4 times in total

Update

Started the car after a while. No warnings. Drove a few meters and still nothing. Gave a raise command and immediately the OFF ROAD MAX 50KM/H appears. Without the car being at off road height. The respective led kept blinking but no raising. I push the knob again up and the off road msg disappears while the car rises.

But

Before completing raise, the HDC inactive / Air Susp warnings come back and the car reverts to standard height.

Thinking back, in the morning, I had it parked on an incline overnight. Getting on the road it seemed like the driver's side (left) front was somewhat lower. I raised to off road height underway (which was completed) and reverted to standard height. The air suspension cycled through standard and highway height normally.

Further update

Started the car again after a while. Again no warnings. Drove a few meters and did a few maneuvers within my compound. Activated and tested the HDC and was okay. Swithed on the cruise control and the light came on as normal. Got in and out and checked the brake lights, all good. Shutting the door, self-level worked.
Got out again, leaving the driver's door open and came back to find the same warnings on the dash

I'm beginning to think this could be a height sensor but does a faulty one trigger the HDC inactive warning, too?

On the other hand, it does seems to self level both with and without the warnings on.

I'm kicking myself for not ordering an IID tool prior to Brexit I'm such an idiot.

Okay, here's some more:

Let it sit for a little longer and started without any warnings. Drove off and went around the wider area on a 20 min ride. Nothing happened. Did not have any suitable long stretch of road to test the highway mode though. But there were several bumps and gratings to shake and rattle things enough. HDC worked fine.
Nearing home, stopped and selected access height. It dropped immediately but the light kept blinking a little longer than usual. Then accelerated and the vehicle automatically adjusted to the standard height, again the light blinking longer than usual. Then selected to raise in off road height. The OFF ROAD MAX notification came on right away and the vehicle slowly continued to rise but the light kept blinking indefinitely. So selected back to standard and the vehicle swiftly dropped to standard height.

Now, however, if I select access height, nothing happens, there is no command light blinking next to access. And when I select off road, the light blinks indefinitely with nothing happening.

Click image to enlarge

Click image to enlarge

This morning started the car and was able to cycle through all the suspension modes. Driving to work we hit the motorway and it even went in and out of motorway mode normally. No warnings, no bong, everything seems back to normal. This is nuts...
I'll observe this over the next few days, no choice, really, as most everything is closed, normal people being on vacation. The worst time to have a breakdown, really. If this turns out to be just a warning shot or a hiccup, I'll use the funds reserved for a possible repair to order that IID tool and call it a day.
Meanwhile, as always, I'm still loving my fat girl...

Ps:...And ordered the IID Tool at last

Last edited by vs322 on 21st Aug 2021 10:29pm. Edited 2 times in total

Not so unexpectedly, the problem resurfaced this morning.
Amber triangle, HDC Inactive, Air Susp. Inactive and suspension locked to standard height.
Now it stays and doesn't go away after a reset or if the car sits for a while.
The new thing is, like the 1st time, which I do remember correctly after all, that on one or two occasions the ABS and stability amber lights also came on. If I pull over, stop and restart, they will clear.

Have so far

Visually inspected the ABS sensor wires

Disconnected, cleaned, insulated and reconnected the wire+ plug to the front left height sensor which seem to have some more tear and wear on them compared to the others.

The problem, as observed over the course of these days appears in any condition. Stationary, in motion, over bumps during idle, with or without occupant in the driver's seat. It now seems to have worsened and setting in permanently.

Process of elimination continues as follows:

Ruling out SAS as the reset after disconnecting battery is always successful either for only the amber ABS and stability lights or for both these amd air suspension+HDC (when everything works)

Ruling out brake pedal switch as lights work normally

Ruling out a height sensor / air valve block as the vehicle self-levels

Ruling out air suspension altogether as this is apparently a symptom, not the cause

The HDC fault is first to appear. Air suspension only follows after a few seconds

HDC is dependent on the ABS, which still works when only air suspension and HDC warnings are active.

NO visible faults with ABS sensors and no obvious corrosion of same

The faults displayed are not predominantly related to the ABS but to the HDC

If DSC button is pressed to deactivate, nothing happens

HDC as well as DSC receive input from an accelerometer or yaw rate sensor

With HDC / Air Susp warnings active, if I disconnect the plug to the yaw rate sensor, I do get the 2 complimentary amber lights for ABS and Stability.

Now if we strip this all off the fancy messages and lights, what we basically remain with, is an amber HDC light.

Had the same on the freelander. Turned out to be the G sensor.

I'm fairly confident this is all caused by the yaw rate sensor which is on its way out or pronounced dead as of this afternoon. Have ordered a 2nd hand one; fairly inexpensive that way.

I'll confirm with the IID tool when it comes in next week. Meanwhile, 45 euros for the used part is a bet I'm willing to place in order to save time.
My only concern is how to actually replace the as the whole rear of the console needs to be taken apart.

Click image to enlarge

Hi VS322, did you ever get to the bottom of the issue?
My vehicle is doing exactly what you described yours as doing.

Cheers

Hi and welcome to the forum! Yes, it was the PCV.

https://www.fullfatrr.com/forum/topic60641.html

Thanks, actually the issue I was following up on was the HDC and Air suspension inactive one.

The faulty PCV was triggering my HDC/AIR SUSP INACTIVE messages in this case/thread.

It's a symptom rather than a fault so another culprit could be the steering angle sensor.

I've done that last weekend, check my recent posts for more info and food for thought. I suggest you got a diagnostic tool such as GAP IID or equivalent.

Feel free to post more about your issue so I/someone else can help you more.

What lights are you getting on the dash?