Rockingit

Rockingit

Active Member
So having fought and won replacing all bushes and the link bar on the rear left, with the drivers side wheel also removed and jacked up, obviously both sets of suspension dropped to the maximum. Having replaced and done a short test drive (joy - it's a different motor entirely!) it's now sunk to the stops on the rear and looks similar on the front, but says air suspension is inactive. Tried the wheel spin reset and doesn't work. I'll get the Autologic out later on, anyone have any quick pointers where I should be looking?

Cheers, R.
 
OK, so this has me confused (in fairness, that's not hard these days).

Using Autologic with LR software :
Looking at the suspension readings and everything is reporting back as I'd expect it to - all four height sensors are claiming numbers that make sense (-100 rear and -50ish front) given the amount it's dropped. And if you bounce it around then they all twitch. It's not reporting any error codes. Have cleared ABS and steering codes as I think I know what they are from anyway so from what I think I know, we should be good to go and reinflate. Except it doesn't. Using the reinflate tool does nothing, although the deflate tool did drop it by another few mm which says to me that the valves ARE active. When you ask to reinflate you can hear the compressor pulsing away but diddly squat happens so there's something else keeping all four actuator valves closed. I ran it for at least half an hour, no joy. Suggestions on a postcard......
 
Rockingit said:
OK, so this has me confused (in fairness, that's not hard these days).

Using Autologic with LR software :
Looking at the suspension readings and everything is reporting back as I'd expect it to - all four height sensors are claiming numbers that make sense (-100 rear and -50ish front) given the amount it's dropped. And if you bounce it around then they all twitch. It's not reporting any error codes. Have cleared ABS and steering codes as I think I know what they are from anyway so from what I think I know, we should be good to go and reinflate. Except it doesn't. Using the reinflate tool does nothing, although the deflate tool did drop it by another few mm which says to me that the valves ARE active. When you ask to reinflate you can hear the compressor pulsing away but diddly squat happens so there's something else keeping all four actuator valves closed. I ran it for at least half an hour, no joy. Suggestions on a postcard......
Click to expand...
Is the compressor actually making any pressure?
 
hopefully this helps to give a general ball park figure

IMG_9049.png
 
Last edited:
DTC's = Diagnostic Trouble Codes = 'Fault' codes
Live values = what pressure values is Autologic reporting for the air receiver, compressor and gallery pressure?

When you say the compressor is 'pulsing', do you mean it's on for 10 seconds or more? or less? what is the pause time between actuations?
Also, what year L322 is it?
 
Rockingit said:
Sorry, you'll have to explain that
Click to expand...

Graculus said:
DTC's = Diagnostic Trouble Codes = 'Fault' codes
Live values = what pressure values is Autologic reporting for the air receiver, compressor and gallery pressure?

When you say the compressor is 'pulsing', do you mean it's on for 10 seconds or more? or less? what is the pause time between actuations?
Also, what year L322 is it?
Click to expand...
Ah, gotcha.

2003 4.4 petrol. And the only fault codes (that I cleared beforehand) related to ABS / Steering (as next job is sort out the steering tracking as that is defintely out, hence the ABS not liking it). I had wondered if it was battery related as that's not as good as it should be but it's left on trickle charge for ages and all the numbers are good both on diags and my meter. This overnight deflation came as a surprise!

I'll take a bunch of screenshots tomorrow.
 
I don't have wiring diags. back to 2003, the later versions did have a 'compressor running' input to the control module via a 5A fuse, if this was corroded or missing (it rarely ruptured) this would cause the compressor to run in 'pulses' for 2 or three seconds, then shut off as the module wasn't seeing compressor control via the relay. When you say 'air suspension inactive' where are you seeing this? on the dash or diagnostics?

Have you tried a battery disconnect / reconnect?
Sorry for all the questions, just trying to get an overview of what's happening (or not!).
 
Is this the right one plse , hopefully it’s useful to members who know these landies better

IMG_9053.jpeg
IMG_9052.jpeg
 
IMG_3116.jpeg
IMG_3117.jpeg
IMG_3118.jpeg
OK, so further investigation - the compressor runs for a good 30secs when the ignition is first turned on and produces air as a I found a leak just after the over pressure relief (fixed by taking an inch out of the pipe and reconnecting). Auto logic says… (and apologies for the daylight screen pics, just easier than messing about with downloads!)…

When using auto logic you can manually switch all the valves on/off and they all seem to work with the exception of the four individual valves, there’s something seeming to hold those off regardless of what you do. The reinflate tool makes the pump run in pulses of 2-3 seconds but nothing else. My next step will be to trace the pipes, find the valve blocks and manually inflate each piston off a compressor just to make the thing drivable again.
 
The reservoir pressure seems very low to me. I would expect to see at least double that figure.
 
Also if the compressor only runs for a few seconds, then something it telling the ECU to inhibit. Rather than using diagnostics to run it, connect 12V & a gauge, and check the output manually. FYI, I have a Wabco pump (very similar to AMK) from a Merc on the bench and it easily produces 200psi into a 5L tank. Tank gets to 10bar in about 3mins.

Then go through the system checking all joints, valve operations, etc. Don't hold 12V on the solenoids, but instead tap a 12V wire on the connection to see if the solenoid clicks on/off.
 
pwood999 said:
Pressure is way too low. The ECU should run the Compressor to these levels depending on which system you have.
Click to expand...

View attachment 307659

Many thanks for this - is the list you refer to a resource on here? (A quick search hasn't thrown anything up). I'll give the direct 12v approach a go with the diags attached and see if the pressure goes up - I assume there's no other switched mechanical valve between the two? 12 bar is a lot of hurt if something goes pop! 😆
 
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