Adblue not registering, gone past 0 miles and wont start. Garage saying ECU issue without checking Adblue system

Gazlad

New Member
Hi all, Im new to this forum and I apologize for the long post but I'm totally lost with the situation I find myself in and I am in need of some help/advise.

I've got a 2021 T6.1 150 LWB. I've had the van for 18 months and I use it as my work vehicle. I do a lot miles in the van, mainly motorway driving and I've put 50k miles on the van since I bought it. I've had put Adblue in the van on several occasions and I generally leave it until I'm able to put 10 litres in, as i buy the 10 litre bottles. I understand now, after reading through a lot of posts on here that I shouldn't leave it to get low but this is the first vehicle I've bought that requires Adblue and I thought as long as I didn't let it got to 0 miles I would be fine. This time I had let it get below 100 miles until the Adblue would prevent the engine from starting and I had to go to job over 100 miles away so I put 10 litres in and then set off. I noticed it didn't register straight away but the time before this it did that but after a bit of a drive it registered and all seemed fine, so I assumed the same would happen here. It didnt, and it went below the 0 miles but i carried on to my destination and thought i will just get recovery out and I can do the job in time i would be waiting for the breakdown company to come and sort it out. The breakdown company came and I told them what i had done and they plugged there machine in and tried everything to clear the faults and try to get around the Adblue system with no luck. The guy said he thought the tank has probably crystalised and the sensor isn't registering the adblue I put in. He said I needed to be recovered and have the van looked at in garage, he told me to there where a lot of faults coming up on his devise that weren't related to the Adblue but maybe there is a fault with the Adblue system and that was affecting the rest. Before this I had no warning messages or lights on the dash about any issues. So I rang the garage I had been taking the van to for my servicing and explained to them what had happened and what the recovery guy had told me and they said they would have to do there own diagnostics so I got it booked in and i had the van recovered to the garage. When we got there the garage was closed so left it outside on the side of the road and returned the next day to get it booked in and give them the keys. The next morning I returned and when I was explaing to the lady on the desk what had happened one of there technicans over heard and said if it was an Adblue issue then they would need to do a check on the Adblue system and that would 3 hours as they have to take it apart and do this, that and the other (sorry im not mechanically minded). I asked whether this would come under warrent and the guy said generally it does when it comes to Adblue system and he asked to find out who my warrenty was with. I spoke to the warrenty company and they informed me my warrnty had expired at the end of march, so spoke to the company bought the van from and basically told me the 2 years extended warrenty I bought hadn't been registered but because I had purchased it from them and didnt register it, that they would honor the warrenty and pay fo the repairs. They just wanted the garage look into and give them a report so they could get the work approved and paid for. I then went back the garage the van was at and istructed them to do the examination of the adblue system and send me the report to pass on. I didnt have anymore conversations with the garage apart from to ring them a few days later to see what was happening and i was told it was booked in for the next day and some one would contact me when it was done. I then received the report a couple of days later (the report is attached) and the report said nothing about checking the Adblue system, instead it listed all the faults from the first examination and said they had investigated a coffee spill on the dash, which they concluded hadn't caused any issues and that they had spent the 3 hours I thought they was using to do a check on the Adblue system checking some wiring, which they also concluded was fine and come to the conclusion there is an issue with the ECU and it needs sending off for further investigation. When i quized them about this and why they hadn't checked the Adblue they said I had voltage reference faults and that could be anything and that it was most likely a nick in the wiring so they had been checking for that but couldn't find anything. They also said there wasn't any faults coming up relating to the Adblue system so they didn't check that and in there oppinian the issue is related to the ECU. Well I wasn't happy about this responce as In my head the issue has come because the Adblue system didn't reckonise I had added Adblue to it and surely the first thing to do is to make sure the Adblue system is working as it should be and then if that all comes back fine then move on to other things, like the ECU.

I've tried talking with garage because i feel they haven't done what i was asking, which didn't go well and they are charging me more than what I was expecting. I've tried telling them im not prepared to pay the bill and dispute it but again that ended very heated, so after taking legal advise I've decide to just cut my loses and pay the bill so I can get the van sorted and back on the road as im in desperate need to get it back on the road.

Im looking for some advice on whether the garage are correct or if checking the adblue system first should have been the correct way of going about this and also if anyone has experienced something similar and had similar faults come up and genearal advise on what I could do going forward.

Thank you in advance for any help/advice anyone can give. As I've said im totally lost and feel extremely anxious about the outcome.
 

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I'm not a mechanic but I know that ECU's log faults that subsequently clear and cause no further issues. The ECU logs them with a date and time and mileage so it can be determined by a competent garage mechanic if these faults are associated with the problem you take the van in for at a later date, if the van has never been read in its life then there could be loads of logged issues that have never manifested into service affecting faults.
Without a direct read of the ecu and a log of the mileage against the fault logged you will be unable to determine if any of those faults are the cause of your issue. Just having the P code and description is not enough to say that any of those fault codes are either pertinent or current.
As a minimum I would have copied the first read of the ECU, cleared the fault codes and then run the van to see if any of the codes returned.
If you didn't have the MIL light lit (check engine) then I would say that none of the codes were pertinent in the cause of the issue you have.
Have they now cleared the codes from the ECU (bet they have) and have they kept the date and mileages when those fault codes were logged (bet they haven't).
If the P056200 fault was logged 3 years ago, it is not a factor in your current fault.
Is the van running now? Has the adblue range come back up to normal?
This is why I don't trust garages with anything more than an MoT.
 
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Im really not sure if any that has happened. I don't have the van back yet, a lot of the talk with the garage happened on Friday and they are closed over the weekend, but as far as I'm aware the van still won't start and is probably saying the same as when I gave it to them. IE it won't start because the adblue is preventing it from doing so because it does think there is any adblue in the system and it's gone past the o miles point
 
The VW adblue system as I know it uses an ultrasonic sensor to measure the adblue level in the tank by seeing a reflection off the surface of the adblue/air barrier, If too much adblue has been added this flat level surface can't be seen by the sensor so it thinks the tank is empty rather than full.It may be possible to decant some of the adblue out to a point where the sensor can again see the surface and give a reading.
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I don't think it should have too much in as I let it get to the point where the van was telling me if I didn't put some in, it wouldn't start in 80 miles and at that point I added 10 litres. Could me letting it get so low crystallised that part and that is then the reason it isn't recognising what I put in?
 
The ultrasonic sensor is outside the tank containment area (because adblue is corrosive to anything left in it) so it's unlikely to be affected by crystallisation.
The normal place for crystallisation to be a factor is in the smaller pipes and injector orifices in the delivery system where it sprays the adblue into the exhaust stream, this usually manifests as a 31103 - SCR NOx Catalyst Bank 1 P20EE 00 [236] - Efficiency too Low code (with MIL light lit) and a Reducing agent quality sensor: urea concentration: 0.00 % in there somewhere. Basically the system is trying to add adblue to the exhaust but it's not seeing the expected effect of reducing NOx levels so it assumes you've put plain water in rather than adblue (urea concentration 0.00%)
 
According to the owners manual you should top up the adblue with the engine off, then turn the ignition on and wait for the adblue to reset (up to 30 seconds) before starting engine.
Some don't do this and have no issues, some do this and it doesn't reset, some say adding fuel at the same time (to the diesel tank not the adblue tank) spurs the van into doing its reset.
Personally I add some adblue (never more than it says on the dash, always less) then go for a drive, it sorts itself out within 10 miles.
 
We have a 65 page thread on Adblue issues in the forum.
 
Your display should have told you the minimum and maximum amount to put in. If you were down to just 80 miles left then there was plenty of room left in the tank. Can you remember what the amounts on the display were, just wondering if the 10 litres you put in was enough to meet the minimum requirement, I think the T6.1 has a bigger tank than a T6. Of course you must be careful not to over fill it either. I wouldn’t be happy with the work the garage carried out as the issue is clearly adblue related.
 
Your display should have told you the minimum and maximum amount to put in. If you were down to just 80 miles left then there was plenty of room left in the tank. Can you remember what the amounts on the display were, just wondering if the 10 litres you put in was enough to meet the minimum requirement, I think the T6.1 has a bigger tank than a T6. Of course you must be careful not to over fill it either. I wouldn’t be happy with the work the garage carried out as the issue is clearly adblue related.
I honestly can't remember how much the warning message said i should be putting in but I've always let it get down to the point it says I could add 10 litres because I've always just bought the 10 litre bottles. I've had a few people tell me to add more but I have been worried about doing that and adding to much, because its in the warranty period and I don't want the warranty people to me tell I've put too much in and therefore the work isn't covered by warranty. Im going to get it from the garage this week and I might just try adding some more cos I have another 10 litres in the back of the van. I'll find out the tank size beforehand and gauge it from that.

As for the garage, I'm really not happy with there response and I won't be taking to them ever again. As I said in the post, I can't understand how they have just ignored the adblue system and are now trying to get me send the ecu off. In my simple mind it doesn't make any sense and even if they are right and it isn't to do with the adblue system, the fact I've asked them to check it, surely then just do it to keep me happy and its money for nothing for them.
 
According to the owners manual you should top up the adblue with the engine off, then turn the ignition on and wait for the adblue to reset (up to 30 seconds) before starting engine.
Some don't do this and have no issues, some do this and it doesn't reset, some say adding fuel at the same time (to the diesel tank not the adblue tank) spurs the van into doing its reset.
Personally I add some adblue (never more than it says on the dash, always less) then go for a drive, it sorts itself out within 10 miles.
Since this has happened I have realised this, mainly from reading other posts on here and on the Internet. I assumed it was just like adding fuel. Put in what is needed and carry on. Once this has been sorted i will be much more careful.
 
Since this has happened I have realised this, mainly from reading other posts on here and on the Internet. I assumed it was just like adding fuel. Put in what is needed and carry on. Once this has been sorted i will be much more careful.
It should be as simple as adding a bit of fuel, you'd think. Not had to top mine up yet but reading up on it
 
Once it has counted down to 0km and the engine won't start, it needs to be reset with a VW specific tool (either by VW dealer workshop or something like VCDS). That will either fix the range back to where it should be based on the Adblue level or give you another 50 miles if it still thinks the ADblue is empty.
As you have probably already read on the forum there is a software bug that can cause this issue, so worth checking what revision software your Engine ECU has and get that updated if it needs to be.
 
As you have probably already read on the forum there is a software bug that can cause this issue, so worth checking what revision software your Engine ECU has and get that updated if it needs to be.
The software update was supposedly done on my van by VW but it didn’t fix anything.
 
Youtube guide on how to reset adblue level, not sure if this applies to the T6 as I've not had to do it as yet.
 
Once it has counted down to 0km and the engine won't start, it needs to be reset with a VW specific tool (either by VW dealer workshop or something like VCDS). That will either fix the range back to where it should be based on the Adblue level or give you another 50 miles if it still thinks the ADblue is empty.
As you have probably already read on the forum there is a software bug that can cause this issue, so worth checking what revision software your Engine ECU has and get that updated if it is
Is that something that a garage can do or would I have to get the ECU sent off to do that? I've found out the T6.1 has a 22 litre adblue tank and I've only put 10 litres in it from pretty much empty, so I was thinking I just needed to add another 10 litres and i was hoping that would sort the issue and I'd be back on the road later today. The place it is at are supposed to be VW specialist and I would assume they have tried to reset it and have had no luck but I will find out later.
 
Is that something that a garage can do or would I have to get the ECU sent off to do that? I've found out the T6.1 has a 22 litre adblue tank and I've only put 10 litres in it from pretty much empty, so I was thinking I just needed to add another 10 litres and i was hoping that would sort the issue and I'd be back on the road later today. The place it is at are supposed to be VW specialist and I would assume they have tried to reset it and have had no luck but I will find out later.
Not all T6.1 have the larger tank. As mentioned above the van tells you a max and min amount to put in. You should follow these instructions or it causes problems. So you can't think "I just need to add another 10 litres".
 
First I would first resolve the faults listed by garage. Either they a glitch in the past - but if they are current faults they definitely need to be fixed first.
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A VW garage should be able to do it with their diagnostic software (ODIS) or it can be done with VCDS as per the post from Grim Reaper
 
Not all T6.1 have the larger tank. As mentioned above the van tells you a max and min amount to put in. You should follow these instructions or it causes problems. So you can't think "I just need to add another 10 litres".
Ok, yeah I see what you are saying. I got that information from the VW T6.1 brochure but I will see what the dash is saying and go from there. If it was the bigger tank and I could add more would it just be a case off adding some more, the system seeing it and then be able to drive or would it still need the computer plugging in and things being reset?
 
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