UREA count down not resetting after AdBlue top up

[seoras]

I then bought a 20L jerry can and some piping and syphoned out as much of the AdBlue out of my car as I could managed.
I got just under 15L out. When I filled it up at the pump it only took 14.3L to fill it. I'm now wondering if in fact my car has a 15L tank.

Was just looking back over the post since there was a reply & just noticed this.
I take it that means you don't know there is a drain plug on the urea tank? (number 5)
You just undo a small torx screw then the plug just twists out. I wouldn't fancy getting a mouth full of urea

Now you tell me....

[seoras]

dear seoras,
I have the same problem, "check adblue system" although adblue is topped up. I also have the same app and I get the 32.766 reading on the non continuus monitor for the nox sensor.
I changed the nox sensor but the problem remained after 200-300 kms.
I will be waiting for your findings, thanks.

Interesting. It is a "non-continuous" sensor so I wonder what the conditions are for it to take a reading.
Perhaps there are certain conditions needed to force it to re-read the value.
Like the emptying of the tank and re-filling.

I do wonder why there are 2 NOx sensors which take readings that give different ranges? I got the other one to re-read by emptying and re-filling.

Now we know there's a drain plug it might be worth checking but you might as well wait a few more days and see what I get told when I take it to the dealer.

[GiveMeABreak]

The NOx sensors (only on certain vehicles that are Euro 6.2 compliant) are intended to measure the overall volume of nitrogen oxides (NOx) and a) one measures the mixture of the exhaust gas downstream of the deNOx system and b) the other one measures the exhaust gas richness upstream of the system deNOx, so you would expect different values.

If you want the operational function / explanation of the sensors I can provide this.

[seoras]

Worst case scenario was realised today except that is was even worse than anyone on here could have predicted.
After an hour with the Citroen Dealer I was told it needed a new AdBlue tank.
I questioned this based on my own diagnostics and they gave me the print out from their software which showed that the AdBlue level, with the tank full, was showing only 2.6L
They said there was no other errors, not even the NOx error that I'd been getting (& still get) using my own car scanner app.
So I'm wondering if the car scanner app is reading an address which isn't supported which would explain why it reads as "111111111111111"

So new tank. Which I'm led to believe from the forums I've read costs ~£1,000.
No, not here in New Zealand. Here it will set me back NZ$4,200 which at today's exchange rate is £2,156
That's just the part without labour.
They have to order it. Which I take to mean ship from Europe. Which, due to CV19, could take several weeks.
I'm down to my last 1,200Kms so my backs really up against the wall here.

Spoke to my local garage who do all the basic servicing and they said they'd have a go if I could buy it direct myself but they don't have the software to initialise a repair.
I've seen the DiagBox software for sale on EBay but most sellers want you to ship your laptop to them - obviously so you don't get the installation CD/DVD and just copy and sell it yourself.

Going to call a few dealers to try and find a comparative quote - or even stock.
Not having a great day, lady luck didn't show up.

[seoras]

Called the dealer who I bought it from 7 years ago. Quoted NZ$1,000 less and they can get a tank by Friday.
It's a 3 hour round trip, instead of a 1.5 hours round trip but that's worth the extra G (& it is a very scenic trip to the beech too!).
Booked it in with them for next Tuesday. Painful but not as painful as it could be.

So what is my next delightful failure going to be with my 7 year old Citroen C4 GP?
So far I've had a string of failures. The colour LCD display failed, alternator tensioner failure which melted the belt when it wrapped around it's wheels, day I bought it the driver wing mirror motor failed (that was funny at the time!) and a few other little things plus a string of re-calls.

Is there a warranty that comes with a new tank in the UK? ie if they fit it and it fails in 6 months?
I'd hope they'd have fixed the issue that caused the early models to fail by now.

[GiveMeABreak]

It's why I mentioned using a bespoke dealer-level diagnostic a few posts ago as third party readers are woefully inadequate and often cannot read the constructor-specific codes.

Citroen-provided original parts usually come with a 12 month warranty.

You've done the right thing, as you would be no better off with a Lexia and the later Diagbox 9.** software as you still would not be able to perform any programming or calibration with it - that is something that only the dealer version can generally do as they have access to their servers for the configuration. Later versions of the software have little to no programming functionality as it has mostly all moved to online telecoding.

I hope that solves it for you.

I will be topping up my Adblue every couple of months. I don't like the idea of leaving it until it gets near empty or for the warning to come on before I top it up, as all that air in the tank with the little remaining volume of Urea is bound to cause crystallisation / oxidation.

[seoras]

I will be topping up my Adblue every couple of months. I don't like the idea of leaving it until it gets near empty or for the warning to come on before I top it up, as all that air in the tank with the little remaining volume of Urea is bound to cause crystallisation / oxidation.

Yep. That's a great suggestion. I think I'll be setting up a periodical reminder on my iPhone to top up the AdBlue so it never dips below 10L.

[RichardW]

That's bad news! In the UK they are offering an enhanced 'warranty' on these tanks - no harm in asking the dealer if they can approach Cit NZ to see if there is something similar? Someone recently got it for free, just paid the hour's labour or something to fit it.

[GiveMeABreak]

I know some owners whose cars were just out of warranty which they covered the cost of the tank - sometimes it will be down to the goodwill they make and often whether you have had it dealer-maintained too.

[seoras]

Car's now repaired at the cost of ~£2k.

Attaching the OBD2 scanner I'm still seeing the first of the two NOx sensors reporting 32.766 so that must be an un-used address by Citroen on my make/model. A Red Herring.

I noticed that the tank cap has changed on the new tank. It looks like a complete redesign.

I don't think they topped it right up to the top either so I might do that myself although I'm tempted to bin the 15L I drained out of the old tank - just in case.
I'm sure if I spray it in one of my fields the grass will grow just great!

[stergioszx]

dear seoras,
I still have not found the problem with my 2016 relay-jumper issue. Sometimes the engine light goes off by itself and comes back.
Apart from that sometimes I see the nox sensor reporting "green" when I use car scanner pro-"non continuous sensors".
Anyway, I just bought a lexia-diagbox and will try to dig deeper.

[Ray123]

Hi,

On my Peugeot Partner 2017 bluehdi van, the hazard warning, engine and UREA light came on. I immediately stopped at a local garage and a mechanic filled the tank with around 16l of Ad Blue, so I'm guessing the tank was almost empty, if not completely empty. I didn’t get any warning lights about the tank being low before this happened. I noticed in this feed that it's advised we wait 5 minutes before opening the driver car door or turning on the ignition. The mechanic in the garage didn't do this and did both of these things within a minute of filling up the Ad Blue tank to see if the warning lights were still on.

Since, all three lights remained on, and then around 50 miles later I had the warning alert saying emission control fault 'starting prevented in 700 miles’.

The tank is full of ad blue, any idea how to fix this issue?

[RichardW]

You'll need to get it scanned (by someone that knows what they are doing) to see what is at fault...

[Gilligano]

Hi all, we've got a 2018 C4 GP which has recently had the ad blue warning light and service light appear at the same time. The ad blue warning for down to 100 miles and we put an initial 4 litres in. No change to the light. Put a further 6l in and no change. Took to local garage who said diagnostics showing error and that it likely needs a new pump, which is c.£500 part only. But to fill tank to see if that reset it. Put more up to full 17l but no change. Both lights still on. Rang local Citroen dealer. Cost for dealer to run diagnostic is £138. Would hate to pay that only to be told what I've already been told.

Only option seems to be pay up or ad blue delete - but we don't want to invalidate insurance obviously.

I read this thread and found it really helpful. I just wondered if anyone has any other suggestions? As a cheap final port of call, i'm thinking of draining the tank and refilling with some fresh ad blue in case the previous one just happened to be a bad batch? I've read that if the urea percentage is not bang on this may result in censor not picking up the refill?

Thanks in advance.

[GiveMeABreak]

Don't delete the Adblue system (we don't condone it on this Forum) - it is illegal to do as your car will no longer meet the certification it was given, and you'll risk further faults, and may fail MOTs in future, as well as pass on the misery of the repairs to the next owner - and of course the insurance issue you mentioned...

First thing is you really need to have read the manual about topping up the Adblue, as there are conditions to be met depending on the warning and level it is at when you top it up - which concerns the minimum amount to top up and the time to wait before opening the doors and turning on the ignition.

Because of this, it may only require a DeNox reset to account for the incorrect filling quantity / ignition issue, which would be a lot cheaper than a new tank assembly if not required. But running the diagnostic will allow them to a) do the reset and b) check to see if the pump module is working and whether there is a simpler issue like the Adblue injector or a supply pipe issue / blockage. That's why you really need the diagnostic to see if it's anything else that is potentially cheaper than the tank...

Be aware we've seen people that have just had the tank replaced and the issue has not been the tank - so £1000 down the drain and still left with the original issue!