Adblue / Additive Issues

[Mexico14]

I'm particularly interested in any relating to the adblue tank cap. I have the count down on my display despite topping up the adblue it hasn't gone. I think citroen may have left me with a compromised adblue tank cap, even though the car has been with them for services and work every year I've had it, 5 and half years.

[GiveMeABreak]

What's the issue specifically? There is supposed to be a countdown for the Adblue. It just remains at the same mileage (1700 miles) for the Picasso until the level of Urea in the tank equates to this mileage remaining, before it starts counting down from there.

If you are saying the Adblue tank has been topped up and the mileage is actually now counting down from 1700 miles, then you have a tank problem I suspect. As its a 2016 model, you may be in the warranty date for the adblue tank if you've had it serviced regularly. Best to check this with Citroen.

There is an issue with C4 Picasso vehicles up to build date 14541 (which includes yours).

If the tank breather is blocked, it can lead to a suction noise when you open the cap. This can lead to distortion of the Urea reservoir tank itself. A way to check if your vehicle is affected is to look underneath the Urea tank and see if it is distorted.

Example of a distorted urea reservoir (1) (at "b").

Check the condition of the urea reservoir (1):
If the urea reservoir is distorted and/or if the urea reservoir (1) filling opening is inaccessible then the repair is to replace the urea filler cap with a ventilated breather.
However, if it is not possible to install the urea reservoir filling tool itself, the second recommended repair is to fit a new reservoir that is fitted with a new cap fitted with a breather.

In order for Citroen to replace this under a tank warranty I think the car must be under seven years old, but in either case you would have to get Citroen to authorise it and to do that they would need to run the checks for a warranty claim.

[Mexico14]

Thanks for your reply.

Yes I've topped up the adblue with 7 litres after the countdown started from 700 miles rather than the usual 1500 it was accompanied with an engine light also.

I was going to top up further in case it hadn't registered. I can see the adblue through the filler hole. I dipped a screwdriver in to the tank, the adblue level is about 4 inches from the top of the filler hole - I assume this is well over halfway?

The adblue alert isn't there when you get back in the car until the engine is started, not sure if that gives any hint to the actual problem or not.

My cap is a blue one with a smaller black bit in the middle - it looks like it has holes in it, would that be an original part or the improved replacement?

[GiveMeABreak]

It's possible you may have the older cap - just about all the replacement ones for your vehicle have a white part in the centre:

[Mexico14]

Should the dealer not have changed that on one of the numerous occasions they've had the car over the years?

[GiveMeABreak]

Well not really, because they will only action something if the customer presents with a specific issue. They would then check to see if there was a TSB about this and undertake the required diagnostics and tests as per the guided recommendations before determining if remedial action is required. So in your case, if they have undertaken some previous repairs and you are still having an issue then you can at least state that your reported the issue previously, so that if a new tank assembly is required, then they may look favourably concerning some contribution.

You can always contact Head Office about this too and mention that you have already been to the dealer (as that is what they will tell you to do in the first instance). If a new tank assembly is required, you explain it has been in for issues concerning the adblue previously and this was not picked up.

Of course, they may say that it was an unrelated issue, or just go ahead undertake the warranty claim requirements and replace it for you.

[Mexico14]

Bit of an update on this.

Yesterday I hit the adblue tank with a rubber mallet and added forte adblue exhaust crystal preventer to the adblue tank. Yesterday and this morning the count down warning light of doom was still on.

The car was put in for a parking brake repair and they said they'd have a look at the adblue issue.
They fixed they parking brake but told me that the nox sensor needs replacing along with the eolys tank. They give me a quote for £800 to replace nox sensor and eolys tank. I thought the eolys was a bit bizarre as it was only replaced in August.

I turned the ignition on expecting to see the count down, but it's dissappeared... I wonder if the forte solution has had enough time to work rather than anything the auto electrician did?

I'm half expecting the warning light to come on again.

[GiveMeABreak]

I think there's an error there - the Adblue tank has nothing whatsoever to do with the DPF Additive (Eolys) reservoir..... I think you better get that clarified before you let them near the vehicle.

[Paul-R]

I've just replied to your PM but we need to be absolutely sure which system we're talking about. Adblue or Eolys.

[Paul-R]

Should the dealer not have changed that on one of the numerous occasions they've had the car over the years?

Not if it was Windsors. My car went in for a service there and a few warranty items and when I went to pick it up I asked about the cap but they hadn't done anything. It was only my asking that prompted the service manager to very quickly get a replacement cap and fit it.

[Mexico14]

I think there's an error there - the Adblue tank has nothing whatsoever to do with the DPF Additive (Eolys) reservoir..... I think you better get that clarified before you let them near the vehicle.

Codes on the diagnostics were:
U0118 ATT
P1435 ATT
U1218 ATT
P20EE MEM
P242F ATT

P160E MEM
B1003 (THIS MAY BE A FALSE ERROR) ATT
B173D MEM
B1715 MEM

There's no lights or warnings on the car whatsoever now.

[GiveMeABreak]

I don't have the details on this engine unfortunately, just some of the code titles:

However, it seems in that there are at least 2 issues going on, a fault with the Additive Pump (which is the Eolys DPF additive fluid) for the first 2 faults below and the fourth one is the NOx sensor for the Adblue System.

The last one below (P242F) is self-explanatory in that the filter is clogged - but this may be explained by the fact that if the Eolys additive pump is faulty and not working, then additive fluid is not being injected into the fuel tank and therefore assisted regeneration won't take place or won't be effective, as the exhaust temperature won't get hot enough to regenerate the filter. The only way to do that is on a highway or motorway where you can get the exhaust temp up to about 550 °C where natural regeneration occurs. The issue with this is that all the short journeys just add to the clogging until you can get to the desired temperature - hence the need for assisted regeneration for these sorts of shorter journeys.

So in summary these would indeed indicate a fault with both systems.

P1435: Multiplexed additive pump: CAN fault or multiplexed additive pump fault
U0118: Multiplexed additive pump: CAN fault or multiplexed additive pump fault
U1218: Communication fault with the built-in systems interface: Communication not valid
P20EE: Depollution of the deNOx system: Emission control ineffective
P242F: Particle filter: Filter detected worn

[Mexico14]

Thank you for the explanation Marc. It seems strange that I didn't get any engine management light relating to the Eolys pump - when it was empty in August it had an engine management light in the app it stated: "Faulty Engine Control System:
Avoid using your vehicle until it has been serviced by a Citroën dealership"

Referring back to a previous thread you mentioned " the engine ECU will need to be informed it has been replaced and the additive counter reset, so depends on whether your mechanic has a professional level diagnostic tool and software to do this."

I'm now wondering, if the mechanic didn't inform ECU of the replacement/counter reset?
Could those codes be a result of a failure to perform the above? Then again, wouldnt it have been showing faults as soon as I received the car back, or could they temporarily clear them?

[GiveMeABreak]

Ok, so the issue with the Eolys additive pump is that the tank has no physical measurement device. So the engine ECU can only estimate the amount of additive remaining in the tank. It does this from the amount it knows was added at factory, then records each metered amount dosed into the fuel tank whenever fuel is added. It then calculates the amount of fluid remaining.

It also uses the service mileage indicator - to determine if there is enough fluid remaining before the next scheduled service. If not, then the low additive warning is flashed up. However, if the additive counter has been reset without any fluid being added for example, then the engine ECU would think there is more fluid in the tank than there is and you wouldn't get a warning!

Now it's not unknown for unscrupulous people to do this if they have a suitable diagnostic tool, in order to get rid of a warning - especially if selling the car on or to pass an MOT shall we say...

So that's just one possibility why you didn't get a warning about the fluid.

[Mexico14]

Would that scenario of the additive counter being reset without fluid being added cause the fault codes that my car is showing? Or is it more a case of the eolys pump failing? Is the pump within the tank housing that gets refilled or another location?

I'm thinking is there any point me taking my car to the dealers for their diagnostics? I'd be hoping that they confirm it's s an adblue tank problem - then I can possibly claim back a percentage of the adblue tank replacement back from citroen.

If the dealers say its an eolys pump issue only and not adblue related, I'd have paid £120 to be told what Ive already been told.