Auxillary Air Control Module or Earth Shunt problem?

[nknight]

My "59" plate van is showing all the symptoms of the earth shunt problem (auxillary heater blows cold air unless on hook up or engine on etc.). However, the VW van dealer has replaced the shunt and the problem is still there. They anow say that after investigating the issue they are 99.9% sure it is the auxillary air control module that's the problem . This part apparently costs an eyewatering £1,700 to replace!

Does anyone know what the auxillary air contol module is and what it does? Is it possible that this module is the cause of the problem with the auixillary heater even though the heater works on hook up?


Nigel

 

[Andresz]

Is the central control panel blue backlight flickering when heating is on and not on hook-up?

 

[SimplyDubs]

My "59" plate van is showing all the symptoms of the earth shunt problem (auxillary heater blows cold air unless on hook up or engine on etc.). However, the VW van dealer has replaced the shunt and the problem is still there. They anow say that after investigating the issue they are 99.9% sure it is the auxillary air control module that's the problem . This part apparently costs an eyewatering £1,700 to replace!

Does anyone know what the auxillary air contol module is and what it does? Is it possible that this module is the cause of the problem with the auixillary heater even though the heater works on hook up?


Nigel

Nigel,

Unlikely to be the control module if it's working on hook up in my opinion.

Does the battery charge drop materially when (let's say from 100% to 40%) the heating tries to fire up and does the control panel flicker? If so, then it more likely the shunt hasn't been sorted properly or the leisure batteries are past their best and not holding a charge properly. (Second case unlikely unless they've been seriously mistreated.)

Rgds
Mark

 

[calikev]

I agree with mark. If the van works with the engine running or on hook up the problem
Must lie with the batteries either your earth is bad or batteries knackered
£1700. I would want the whole heater for that :laugh2

 

[James]

http://www.ebay.co.uk/sch/i.html?_sacat ... nic&_rdc=1

Just thought I'd add these

 

[nknight]

Is the central control panel blue backlight flickering when heating is on and not on hook-up?

Control panel light flickers (as do the interior lights) when the heater starts up for a few minutes then flickering stops but heater fan speeds up and blows cold air.

 

[Andresz]

Is the central control panel blue backlight flickering when heating is on and not on hook-up?

Control panel light flickers (as do the interior lights) when the heater starts up for a few minutes then flickering stops but heater fan speeds up and blows cold air.

They are 99.9% sure it is the auxillary air control module that's the problem, I am 99.9% sure this is earth shunt problem.
I wonder how they addressed the earth shunt issue ? Perhaps they only tightened the existing tiny bolt. Do you have a thick cable attached to the archwheel under the fridge, inside the cupboard ?

 

[nknight]

Nigel,

Unlikely to be the control module if it's working on hook up in my opinion.

Does the battery charge drop materially when (let's say from 100% to 40%) the heating tries to fire up and does the control panel flicker? If so, then it more likely the shunt hasn't been sorted properly or the leisure batteries are past their best and not holding a charge properly. (Second case unlikely unless they've been seriously mistreated.)

Rgds
Mark[/quote]

Hi Mark,

I haven't seen the van for 2 weeks whilst its been in for repair, and only spoken with the Van Centre by phone , so I don't know what is actually happening now when the heater is switched on. Before it went in the battery charge did sometimes drop as you have said, but not always. Sometimes the control panel would show an "overload" message when the heater was switched on.

I think the batteries are fine. The van is used regularly and I've never run them down to less than 40% charge.

I'm going to check what's happening with the heater and what the Van Centre has actually done tomorrow. I'm told the lead was changed, but I'm I am wondering whether it has been done properly.

Regards,
Nigel

 

[nknight]

Is the central control panel blue backlight flickering when heating is on and not on hook-up?

Control panel light flickers (as do the interior lights) when the heater starts up for a few minutes then flickering stops but heater fan speeds up and blows cold air.

They are 99.9% sure it is the auxillary air control module that's the problem, I am 99.9% sure this is earth shunt problem.
I wonder how they addressed the earth shunt issue ? Perhaps they only tightened the existing tiny bolt. Do you have a thick cable attached to the archwheel under the fridge, inside the cupboard ?

I'll check for the thick cable and find out exactly what the Van Centre have done tomorrow. They say they did fit the new lead but I'm wondering if they have done it properly. I'll probably end up getting a second opinion on what they have done.
Regards,
Nigel

 

[nknight]

I agree with mark. If the van works with the engine running or on hook up the problem
Must lie with the batteries either your earth is bad or batteries knackered
£1700. I would want the whole heater for that :laugh2

Me too but it probably still wouldn't work! And to think we bought this van new to avoid this sort of bill and problem.

 

[nknight]

The Van Dealer has confirmed that they replaced the earth lead to the auxillary battery with a thicker one and replaced the connection (which I take to mean the connection to the body). Looks like they have done the full job.

The Van Dealer has put in a technical report to VW to for their opinion as to whether the auxillary air control unit is the problem. TheVW have asked to supply some further data and are going to contact me again with a diagnosis. The 99.9% sure it's the auxillary air control unit seems to have gone for the moment.

On the earth shunt problem generally, I had previously ccontacted VW Customer Care as I wanted to see whether they would pay for the earth shunt work out of warranty. They say that after investigating the matter with their technical people the earth shunt problem only applies to the 2006 model year and that accordingly, the only VW technical bulletin for the problem applies to vehicles of that model year only. So according to VW, my vehicle which is a 2009 model year isn't affected (even though it was displaying all the symptoms of the problem) and nor will 2007-2008 vehicles have been!

I'm going to wait for the next diagnosis before deciding what to do next.

 

[SimplyDubs]

My 2009 was definitely affected by the earth shunt issue... Fixed under warranty.

All the usual symptoms... Resolved by the earth change... I know of several other in the 2009 model year that also suffered so just a little perturbed by he feed back that it only affected 2007 model.

I challenge that.

Rgds
Mark

 

[nknight]

My 2009 was definitely affected by the earth shunt issue... Fixed under warranty.

All the usual symptoms... Resolved by the earth change... I know of several other in the 2009 model year that also suffered so just a little perturbed by he feed back that it only affected 2007 model.

I challenge that.

Rgds
Mark

That's useful to know Mark.

Thanks,

Nigel

 

[Freeley]

Same here....my earth shunt also replaced under warranty.
I do have some light flickering again though so maybe it's going faulty again.

 

[Andresz]

The Van Dealer has confirmed that they replaced the earth lead to the auxillary battery with a thicker one and replaced the connection (which I take to mean the connection to the body). Looks like they have done the full job.

The Van Dealer has put in a technical report to VW to for their opinion as to whether the auxillary air control unit is the problem. TheVW have asked to supply some further data and are going to contact me again with a diagnosis. The 99.9% sure it's the auxillary air control unit seems to have gone for the moment.

On the earth shunt problem generally, I had previously ccontacted VW Customer Care as I wanted to see whether they would pay for the earth shunt work out of warranty. They say that after investigating the matter with their technical people the earth shunt problem only applies to the 2006 model year and that accordingly, the only VW technical bulletin for the problem applies to vehicles of that model year only. So according to VW, my vehicle which is a 2009 model year isn't affected (even though it was displaying all the symptoms of the problem) and nor will 2007-2008 vehicles have been!

I'm going to wait for the next diagnosis before deciding what to do next.

Flickering lights are caused by the voltage drop on earth connection (shunt) in the situation where high current flow is required to initialize the heater. Simple: if lights are flickering the voltage does drop, which for the control unit of Webasto is a signal that batteries are discharged, hence to shut down the heater.
The heater would never work steady with unstable voltage. Only after assuring stable voltage they may jump to other elements, like the control panel.

Also, there might be different ways to adress the issue of earth shunt, one would be to just tighten the existing installation, which may work for some period of time.
Even making it properly with a longer bolt replacing the stock short one, and additional thick lead connection to the empty seat belt hole in wheelarch may fail after a time. There is a hostile enviroment here: vibrations, salty air from human breathing, temperature changes, extremely high currents in extended period of time. So, earth shunt even once repaired may need to be corrected again after some time.

Moreover, it is a good practice to tighten all bolts sitting on the both batteries clips. There is several of those bolts; only on the PLUS clip under the left seat battery there is 3 or 4 bolts. I tightened all of them in my 2006 van and practically each of them was somewhat loose.
The fuse on the PLUS clip of wardrobe battery also gets rusty and loose.

 

[nknight]

The Van Dealer has confirmed that they replaced the earth lead to the auxillary battery with a thicker one and replaced the connection (which I take to mean the connection to the body). Looks like they have done the full job.

The Van Dealer has put in a technical report to VW to for their opinion as to whether the auxillary air control unit is the problem. TheVW have asked to supply some further data and are going to contact me again with a diagnosis. The 99.9% sure it's the auxillary air control unit seems to have gone for the moment.

On the earth shunt problem generally, I had previously ccontacted VW Customer Care as I wanted to see whether they would pay for the earth shunt work out of warranty. They say that after investigating the matter with their technical people the earth shunt problem only applies to the 2006 model year and that accordingly, the only VW technical bulletin for the problem applies to vehicles of that model year only. So according to VW, my vehicle which is a 2009 model year isn't affected (even though it was displaying all the symptoms of the problem) and nor will 2007-2008 vehicles have been!

I'm going to wait for the next diagnosis before deciding what to do next.

Flickering lights are caused by the voltage drop on earth connection (shunt) in the situation where high current flow is required to initialize the heater. Simple: if lights are flickering the voltage does drop, which for the control unit of Webasto is a signal that batteries are discharged, hence to shut down the heater.
The heater would never work steady with unstable voltage. Only after assuring stable voltage they may jump to other elements, like the control panel.

Also, there might be different ways to adress the issue of earth shunt, one would be to just tighten the existing installation, which may work for some period of time.
Even making it properly with a longer bolt replacing the stock short one, and additional thick lead connection to the empty seat belt hole in wheelarch may fail after a time. There is a hostile enviroment here: vibrations, salty air from human breathing, temperature changes, extremely high currents in extended period of time. So, earth shunt even once repaired may need to be corrected again after some time.

Moreover, it is a good practice to tighten all bolts sitting on the both batteries clips. There is several of those bolts; only on the PLUS clip under the left seat battery there is 3 or 4 bolts. I tightened all of them in my 2006 van and practically each of them was somewhat loose.
The fuse on the PLUS clip of wardrobe battery also gets rusty and loose.

Hi Andresz,

Your comments are appreciated.

Nigel

 

[nknight]

Same here....my earth shunt also replaced under warranty.
I do have some light flickering again though so maybe it's going faulty again.

Thanks. If anyone else has had a later than 2006 model year van repaired under warranty for the earth shunt, it would be good to know, even though I'm out of warranty, given that VW denying the problem exists on the later vans.

 

[nknight]

GOOD NEWS, I think.

Van Dealer has called to say they think they have resolved the problem and hey it turns out it was an earth problem all along!!!

They are going to tell me tomorrow everything they have done and I will update the thread later with the details and hopefully confirm all seems well.

Regds

Nigel

PS The van went in with the problem on 7th January

 

[calikev]

Great news Nigel let's hope it is now sorted

 

[Andresz]

GOOD NEWS, I think.

Van Dealer has called to say they think they have resolved the problem and hey it turns out it was an earth problem all along!!!

They are going to tell me tomorrow everything they have done and I will update the thread later with the details and hopefully confirm all seems well.

Regds

Nigel

PS The van went in with the problem on 7th January

21 days seem to be quite a hefty period for the Earth Shunt repair. I did it by my own in one morning. well; the research how to do it took me about a week

http://www.youtube.com/watch?v=BVuNrNuRJM0

(so much time left for vodka drinking !) :smile

 

[nknight]

I've now confirmed that the earth work carried out by the VW Van Dealer has cured the auxillary heater problem. What's more there is now no interior light or control panel flicker at all when the heater is started off hook up. Since there has always previously been a degree of flickering, I conclude that there has been an earthing issue with the van since new, although not previously serious enough to cause the heater to completely malfunction.

The dealer did the earth shunt repair, and although this apparently didn't cure the problem, I bet it needed to be done as part of the overall process of resolving the earth issue. They also created three additional earths, one to the free seatbelt anchorage point (as suggested by Andresz, but arrived at independently by the dealer (unless they have been reading this forum)) one from the fridge and a third which I'm unsure of the details of.

In recognition that things could have been done better, the dealer has not charged me for any of the work undertaken, and I give them full credit for this. In the end (fingers crossed) they seem to have done a good job. I've had a call from VW as well so maybe they have helped out, although as far as they are concerned there is no earth problem with pre-faclift vans since the 2006 model year.

Anyone still in warranty on a pre-faclift Cali that is experiencing flickering lights or very occassional malfunction of the heater problems should in my opinion get the earthing on their vehicle checked out before the warranty expires. Those out of warranty should press for the work to be done free of charge. Remember the VW warranty does not affect your statutory rights.

Thanks to everyone who took the trouble to comment on this thread. Your comments were very helpful. Andresz, you clearly know your stuff. Nigel

 

[Andresz]

Hello Nigel

I am truly happy hearing that you have this thing off your head, now.

I remember my huge relief at this stage.
I was in even worse situation, because in France where I am based, none of the VW garages confirm any knowleadge about the issue. So I had a choice: either drive to UK, where people are smarter or take the challenge and do it by my own. (I am sure that in Poland it would be the same as in France, since there is very few such vehicles there.)

In the end of the day, this is very simple operation, especially for people who went throuth it already. I am really dissapointed that VW did not make a re-call to address the issue in each vehicle, it would not cost them that much. Repair kit is 25 Euros, and for a repairemant who did it before it is 2 hours job.

Enjoy your heating Nigel.

Regards
Andrzej
Poland / France

 

[nknight]

Hello Nigel

I am truly happy hearing that you have this thing off your head, now.

I remember my huge relief at this stage.
I was in even worse situation, because in France where I am based, none of the VW garages confirm any knowleadge about the issue. So I had a choice: either drive to UK, where people are smarter or take the challenge and do it by my own. (I am sure that in Poland it would be the same as in France, since there is very few such vehicles there.)

In the end of the day, this is very simple operation, especially for people who went throuth it already. I am really dissapointed that VW did not make a re-call to address the issue in each vehicle, it would not cost them that much. Repair kit is 25 Euros, and for a repairemant who did it before it is 2 hours job.

Enjoy your heating Nigel.

Regards
Andrzej
Poland / France

Yes great to have the van back, but a shame VW still in denial over this problem.

Nigel

 

[Bubble]

Hi all

Attempted the earth shunt problem with success recently! I've uploaded a video on YouTube for anyone to view.... Gave me a few laughs watching it back but if helps anyone it's sure worth it..
Please note that the battery is positioned under passenger seat not drivers as mentioned.. Thanks to all the advice on this forum from VIP,s etc . Couldn't have done it without you... Heating starts up with no faults.

Any questions please ask but nothing too technically ha

 

[Bubble]

Here's the link as promised

http://www.youtube.com/vwbubble