Hi guys, I've got a 2004 L322 in with an air suspension problem that I'm struggling with.
It comes up with the "air suspension inactive" message on the dash and nothing works.
It has been to at least one other garage that have just tried the "replace stuff till it works" method.

the codes I got were
01 Left front valve component faulty
02 Right front valve component faulty
20 Front level valves voltage supply faulty
and
Front crosslink valve faulty.

Now it's an '04. it doesnt have a front crosslink valve. This makes me think that at some point soneone has swapped the ECU for an earlier one.

I have calibrated the ride height sensors. I have installed a relay in to the connector for the front crosslink valve to fool it into thinking there is a working one connected.
I have checked all the wiring for any breaks or high resistances.
I have, via the diagnostics, managed to inflate and deflate each strut as desired and pump the car up to within one or 2 mm of normal ride height.

I have found faults with the towbar loom and control box ( very corroded ) it was putting the car into tow mode when nothing was connected. I have disconnected the towbar wiring loom and the control box.
It now nolonger thinks it is connected to a trailer when it isn't.

I have checked the pins at the ECU and I have cleared all fault codes

This is now where I'm at :

"20 Front level valves voltage supply faulty" cannot be cleared, it reappears.

The air suspension still doesn't work - no lights on the control knob and I'm still getting the error message on the dash.

If I unplug the connector to the rear level valves, I can get it to give the same error.
What I don't understand is how it can have a voltage supply problem to the front level valves, but not the rear.

Can anyone help?

All L322's from 2002 had crosslink valves both front and rear....Hidden behind the wheel arch liners

No, the front cross link valve was deleted for the '04 model year. You can see where it would mount. The connector is tied up just out of the way.

sidewaysste said:

No, the front cross link valve was deleted for the '04 model year. You can see where it would mount. The connector is tied up just out of the way.

Click to expand...

Well b*663r me sideways with a pitchfork.....didn't know that....researched and confirmed.....

Thanks for the correction....

Does anyone have any ideas?

Out of interest, what diagnostics are you using?
When did it start having the problem, was anything else changed, removed, added, height sensors not been off and put back the wrong way around or anything ?
Battery is good ?

Snap On Ethos, Snap on Solus Pro and Mac MentorTouch. I don't know what has been done elsewhere, or when the problem started but it seems the height sensors are ok as they caibrated fine with the Solus Pro. The battery seems fine, it holds charge and I've even had the vehicle connected to an external power source.

Can you locate and identify the ECU to see if it's the correct one . I have had really strange diagnostic faults in the past like when I had many lighting issues reported on both allcomms and fault mate which turned out be faulty rear number plate LEDs but not a single fault reported related to number plate bulbs so you could have a fault that is not directly related to the fault reported like water ingress in the rear spare tyre well or the EAS ECU

I wondered about that, the build date for the air sus ECU is a year earlier than the car (or any other ECU) I have no proof but I do think it might have been changed.
I can't see any signs of water ingress anywhere. If only I had a known good ECU from an '04 on that I could try!

Not sure if you can tell from the ECU part number compared to your chassis number as to whether you have the correct one ?

Well, I'm still nowhere with this car.
I finally bit the bullet and ordered an ECU (RTQ000013) as it says it supercedes the one for the vehicle and...
No luck. Still showing a 02 Right front valve component faulty fault.

I just don't understand how this can be so as the valves have been swapped front to rear, so the supposed faulty valve is now connected to the rear strut yet it isn't showing a fault with the rear valve.

It appears to defy logic. the local landrover dealer were ^&*&%* useless as they didn't know what flashing an ECU meant and said that they could plug it in and see what the errors were for £50. They weren't interested in helping diagnose the fault and when I started to describe what I'd done so far, their answer was "well you've gone further than we would mate, we'd just start replacing components by then"

I'm at my wits end.

I just did a quick google on the code you are getting and the BMW sites came up with a few hits, one saying the code 20 is front left ABS sensor and one the same thread it said the text below, totally different car but still BMW, you could try the bimmerfest forums for the X5.
My suspension , among other things locked out the other day saying front left wheel speed sensor, and i kept clearing it until eventually it gave up and now is fine but you could check your abs wiring just for a laugh.

"20 Wheel sensor/inlet valve front right - Check connection between valve and master relay and that master relay and valve are functioning properly."

it may be worth having a scan around the BMW forums and also seeing if you can plug it into an allcomms as its rangey specific.
Reading your post about the towbar electrics, as this locks out the EAS when connected, i wondered if the wiring has been damaged somewhere by a short circuit which would also explain that why swapping the valves front to back had no effect
The site is here
http://www.bimmerforums.com/forum/showthread.php?1236798-ABS-ASC-Code-20

Hi Sidewaysste, Did you get to the bottom of this fault? I have exactly the same issue.... any help greatly appreciated.

Regards John.

I just wonder if you ever got to the bottom of this.?
for me i would check all four height sensors on a live read out and make sure that all ref volts are between 2-5volts and that the @ccompanying individual Height measurement reading are positive readings ( mms)

i have all comms but use my Carsofti930 for this particular job ( it also reads speed sensors’live’ which is also a great help)...
if these are not correct you will get a fault which if not before will pull up the inactive sus fault once driven..