Viano W639 2011 air suspension issue

[Remote Rural Life]

Hello
I enjoy reading the help people receive on this site. I am now in need myself.

I have a long wheelbase, 3.0 CDi Viano, Ambiente, 2011 plate, W639. The air suspension (yes, I hear some of your groan) seems to have decided to stop working. It did work when I first got the car a year ago, and I feel it has stopped working in the last few months because of the banging felt and heard when going over pot holes, which didn't seem to be an issue before and the pot holes are always there.

So, what are the symptoms:

There is no warning light on the dash. The rear sits low, but evenly low. The rear buttons do not do anything when pressed for a few seconds and the auto light on the single button doesn't go on or off (it is always off now). There is a slight noise when turning on the car as if a compressor is working, but when the fuse is removed (the one I think is for the suspension) that noise is still heard so it is either not the right fuse or something else making a noise and that would mean the compressor is probably not working. I can't find the control unit to see if that has a problem - I have seen from other posts that it is in the rear right panel where the jack is stored - but that area only has the jack and other repair tools. The rear button wires just go upwards in to a wire bundle, I can't trace where they may connect to the ecu.

I bought an iCarsoft CR Pro plus this week but it doesn't seem to recognise the Viano, and states that there is no air suspension, and can't do a full scan because it gets stuck at 25% on the rear aircon. So that is having to be returned.

It is probably the compressor and or a leak somewhere but I like to understand all the info before I plunge in spending money, and there are some unanswered issues.

My questions are:

If the compressor was faulty - would that show as a fault on the dash?
If the air springs had a leak or the pneumatic lines were faulty - would that show as a fault on the dash!
Why don't the rear buttons work?
Where is the ecu?
Where is the compressor, I know it is underneath - somewhere...?

I would be so grateful for some guidance. I am struggling to find an independent garage that can help with the Viano diagnostics because some class it as a commercial vehicle. I live in the west of Scotland so choice is limited any way.

 

[MinionBob]

My first port of call would be to check the compressor off the vehicle. It's on the underside, cant remember which side. The compressor might turn on but is perhaps at the end of its life so does not have enough oomf to jack up the vehicle.

Not sue if you know but the buttons only work after certain driving parameters are met, so its something like vehicle has, within say the last 5 minutes been driven over 5mph and, I think ignition is on. I cant remember exaclty. I always find it a bit random it that I can never raise/lower the vehicle when its convenient for me!

 

[M80]

If the suspension isn't / can't lift, the level sensor would see that,
so checking the arm hasn't snapped is a 1st check.

If the system isn't high enough the dash will alarm, in red.

Compressor is n/s, above and forward of the rear wheel. It sits topside of a plate.
But even if the arm is broken I would expect the rear buttons to operate the compressor.

The system doesn't detect leaks, just the height level.

Attached is a diagram, to show correct fuses.

icarsoft should recognise the Viano, mine does. Can you be sure you don't have a poor clone?

Where in W Scotland, we drove up to Inverness earlier?

 

[Remote Rural Life]

My first port of call would be to check the compressor off the vehicle. It's on the underside, cant remember which side. The compressor might turn on but is perhaps at the end of its life so does not have enough oomf to jack up the vehicle.

Not sue if you know but the buttons only work after certain driving parameters are met, so its something like vehicle has, within say the last 5 minutes been driven over 5mph and, I think ignition is on. I cant remember exaclty. I always find it a bit random it that I can never raise/lower the vehicle when its convenient for me!

Thanks MinionBob. I found the compressor, thanks, it is nearside rear. Looks a challenge to get off but here goes. I think those rear buttons do seem unhelpful for the rules under which they work, but I am sure I will love them when they do work at all.

 

[Remote Rural Life]

If the suspension isn't / can't lift, the level sensor would see that,
so checking the arm hasn't snapped is a 1st check.

If the system isn't high enough the dash will alarm, in red.

Compressor is n/s, above and forward of the rear wheel. It sits topside of a plate.
But even if the arm is broken I would expect the rear buttons to operate the compressor.

The system doesn't detect leaks, just the height level.

Attached is a diagram, to show correct fuses.

icarsoft should recognise the Viano, mine does. Can you be sure you don't have a poor clone?

Where in W Scotland, we drove up to Inverness earlier?

Thank you, M80 . I will check the arms. Thanks for the diagram. V useful. Which iCarsoft model do you have. We went for the CR Pro plus thinking if we changed cars then we'd still have a diagnostic tool. Perhaps we should have stuck with the MB V2...
I live in Argyll, very south west to Inverness, below the Great Glen and on towards Ireland, the biggest village is the beautifully named Tighnabruaich. Hope you have good weather.

 

[M80]

Yes that is way down. We drove up, leisurely with a few stops, from Ayr.
Tbh expecting 'good' weather is more likely to disappoint, so anything other than being washed out is a bonus.

Have you ever used the rear buttons? You've to keep the forward button pressed for 2 seconds to cause them to work, that extinguishes that buttons LED, then should be flashing as the rear buttons are pressed. You will hear the compressor 'if' it kicks in.

I have the iCarsoft V2, it works, but I'm not as impressed as others seem to be. I feel it is under developed for the 639.
There is near no availability within the OBD menu. It's the canbus menu that is the usable option.

 

[MinionBob]

If the suspension isn't / can't lift, the level sensor would see that,
so checking the arm hasn't snapped is a 1st check.

I think i am correct in saying there are two arms - 1 per side, so unless both arms have snapped (possible, but unlikely) or both level sensors are dead then that suggests to me the compressor as the OP says the rear sits 'evenly low'. Also, logically I think (mine has never broken so i don't know!) the buttons should/might still work if the level sensor is dead as I would reason you are over-riding the level sensors when using the buttons.

But, as you correctly allude to, if the pump is faulty (and one of both sensors OK) then the vehicle would not auto-level and in turn throw an error on the dash, so a conundrum.

Either way this looks like an under the car mechanical issue.

OP - I think i am correct in saying there are also car tyre valves (Schrader?) somewhere on the air bellows so they can manually be pumped up to check for leaks FYI

I have a Icarsoft - I think the general design is now a bit old relative to the Chinese autel/topdon etc type clones that can be had for £200

HTH

 

[Remote Rural Life]

Thank you both for your help. The arms look intact. The rear buttons do nothing even after being pressed for many seconds. There don't appear to be any helpful tyre valves near or on the air bellows.

The iCarsoft thing is a puzzle. I agree it may not be the best but at the moment it is what we have. A software update has improved things a bit - it does now do an auto scan instead of getting stuck at 25%. However, it still says there is no electronic levelling system. In your experience is it possible that a system can shut down and thus become invisible to a scanner...and if this has done that, is it only a Star system that can re-engage it?

 

[M80]

I haven't interrogated the rear air suspension, so can't comment on what to expect.

I don't recall any schrader valves in the system. The air suspension units merely have an air line into them.
Be careful if you attempt to disturb those, the olive can break easily.

The controller (A639 446 03 17) is over the o/s wheel arch. It's behind the rear panel of course, and bolted with a torx screw.

 

[Remote Rural Life]

Oooh. We have been searching for the controller, the inside of the boot looks like a crime scene. When you say 'behind the rear panel of course' I presume you mean really difficult to get to 'of course'? We looked where the jack is but nothing there, is it behind the fancy panel stuff the jack sits in?

 

[M80]

I store all sorts in the o/s area.
Remove all gubbins, you may not need to remove the foam boxing at the bottom.
But with a torch look forward behind the panel.
There is an steel bracket diagonal atop the wheel arch, the controller will be screwed to that.
It's sharp round there, keep plasters handy,
it's awkward, but I'm fairly sure it only one screw holding it.

I had the panel off for sound proofing, so used the ease of access to reposition the controller, just in case.
But really re siting it in a foam surround would be good enough later.

 

[Remote Rural Life]

I will go do now!!!!!! (rephrase, I will go ask he-who-can, to go do now!). We have spent hours trying to find this little critter. Thank you. I will be back.

 

[Remote Rural Life]

Hours later...we found the control unit, thanks to M80. Tricky to get out, as described, but managed it. I am glad we don't have the extra long wheelbase Viano. Control unit looks fine. By connecting the loom sockets with wire (sockets for pin 1 for power & pin 5 for the compressor), we got the compressor to make a noise. But putting the control unit back in was the same as before - nothing. Went for a drive - no compressor noise, nothing from buttons in the back (pressing for more than 2 seconds). In order to be able to drive the car to somewhere with a Star gadget, my husband is ok about trying to make the compressor work again with his wire trick (being mindful of heat and potential damage) but wonders if the valves to the bellows will allow air to pass if using manual operation of the compressor... any thoughts on that? Also, any ideas on how you can check if a control unit is working and it is something else not letting the process work, or does it look like the control unit is the guilty one at the moment? iCarsoft system still denies electronic levelling system exists.

 

[M80]

Just thoughts, not definite knowledge.
Star would imitate the controls and tell the system to rise / fall.
From the success / failure it would then take you through a diagnostic route toward resolution.

When home I can do a test and prove that theory. But since anyone with Star is likely to charge more than the controller cost I would be tempted to buy one and hope that is the issue.
Not daft to buy 2nd hand off ebay (not via the eu as that complicates things nowadays). as a faulty unit goes back to seller. But since I don't hear of this issue (tempting fate, o 'eck) the likelihood of a 2nd hand unit being faulty seems unlikely.

Tbh dropping the plate to get to the compressor, so as to feed it 12 volts (to test it) isn't difficult.

 

[MinionBob]

My thoughts too about the controller - probably easier/cheaper to find someone who is breaking a vito/viano.

 

[Remote Rural Life]

Thanks again, M80 & MinionBob. I have looked for second hand controllers and the prices on eBay range from £150 to £400. Must be made of gold! The 'nearest' indi MB garage to me that avoids me having to go to Glasgow, is in Ayr. They charge £65 plus VAT per hour for diagnostics, so I do have the price of fuel/ferry to get there but at least it has a hope of showing if it is the controller or not. I have also been told that if you put in a new controller then it has to be taught what it is by a diagnostic system, so I am still forced to do diagnostics somewhere...I am really grateful for your help. Especially M80 for explaining where that controller was, we had looked there and just didn't think MB would be so mean to put something there. We have so much to learn! Thanks again.

 

[M80]

It would surprise me that the controller needs coding, but could be wrong.
For instance I can confirm that a 2nd hand SAM will plug and play.

But yes I did see that ebay prices are shocking, the £65 ph is cheap.

Did you break open the controller to look for burnt components? That might giver an obvious clue as to it being goosed.

 

[Remote Rural Life]

I will let you know about the controller and coding when we get that far, but we did open it up and it looks as new, no signs of anything burnt or wet. I am starting to think that something happened when the driver's airbag was replaced earlier this year for that recall. Maybe someone switched the wrong thing off and then didn't restart it on Star - clutching at straws but it is all very odd. I am hoping the diagnostic scan may have some dates of events happening. I will post on here when we know more.

 

[M80]

If you have electric side doors they will occasionally forget they are electric. Pulling the fuse for that door will reset it. Have you tried pulling the fuse for the suspension, you might be lucky?

 

[Remote Rural Life]

I like your thinking, we tried it just now, but nothing. But keep 'em coming!