Citroen Relay 2021 2.2 SS enterprise Ad Blue problem

[Tommohawk]

Hi all.. another Adblue issue. Van as per title converted to camper over 1 year period, so little used. Took for service couple of months back, not sure if Adblue topped up.
Away on trip and got check Adblue system message but not the no start in X miles message. Drove maybe 25 miles further seemingly running normally.
I've checked with my local garage back home (about 50 miles away) they can read / clear codes. I'm inclined to try Forte additive as simple first resort. My concern is if tank is dry it might burn out pump if I drive home But if I top up tank I can't get additive in .
I can't find any way of checking Adblue level.. am I missing something? What's best advice please.

[PaulC5]

I have found that a service does not include filling the adblue tank at a main dealer. When I top it up I just keep adding until it sounds nearly full as when filling up with diesel. I put in Wynns crystal clean and protect before topping up. The 308 uses about 1 litre every 1000 miles and the Cactus 1 litre every 1500 miles so if you know when it was last filled up it might give you an idea if it needs filling.

To check the level you might be able to poke something like a bit of cable in the tank and use it as a dip stick.

[Tommohawk]

Thanks for that. I've had the van about 12 months but only done about 500 miles. My VW car gives plenty warning re adblue low, so TBH I never thought to check. I wondered re dipstick idea but tank is quite shallow and not sure what that will tell me... plus as I'm away I don't have anything I can use. Bit of stick I guess but don't want to risk contaminating tank....
Well I tried the dipstick idea and seems to have a few inches of fluid but hard to tell as it bends round corner. I think I'll put maybe a litre of adblue in ASAP just to be sure pump doesn't run dry, then drive home and put in double shot of Forte fluid and top up with Adblue as necessary. At least the potholes should shake it all up ok.
I'd be really grateful for any input please!
One question.. if I get codes cleared and Forte fluid dies the job, should it stay cleared? I ask because on O'Riley,s video he resets something else to show unit replaced.

[Tommohawk]

Latest is: I put a litre or so ad adblue in tank just in case it was dry and level sensor was faulty, and drove home. Unfortunately on way home I got no start in 275 miles warning.
When I got home I put in double dose of Forte crystal remover, and topped up with Adblue - it only took about 4 litres total so it cant have run dry. (Unless tank collapsed - hopefully not)
I then agitated it all (F1 tyre warm up) and mild Italian tune up to hopefully clear any crystallisation on injectors. Tomorrow I'll get codes read and hopefully cleared by local garage. His view is it might be related to Eolys fluid issue... which doesnt bode for any diagnostic or repair work!
Unfortunately my tried and trusted garage doesnt have enough height for my H2 van, so I've had to move on.
Quick questions - Does anyone know which of the Launch diagnostic products will read and clear Adblue codes? Grateful for any input!

[Paul-R]

It won't be anything to do with the Eolys. They are different processes with the only similarity being that they have part of their systems being located in the exhaust system.

[PaulC5]

If you have a 000 button on the dash press it and if the adblue range is below about 1500 miles it might give the remaining range. You can read what it says about adblue in the handbook, if you do not have it with you it can be read following this topic viewtopic.php?t=63208

There is also a long topic on adblue to read viewtopic.php?t=81429

As Paul-R has pointed out it will be nothing to do with the eolys. The eolys system injects in to the fuel tank and not the exhaust when the fuel tank is filled but ends up in the exhaust to allow dpf regenerations at a lower temperature.

[Tommohawk]

Thanks for that guys. Yes, appreciate Eolys and SCR unrelated... which is why I dont have much faith in the garage who suggested Eolys might be the issue.
Thanks for the link to the handbook - very helpful.
I read that long thread and it looks to be specific to pump pressure and gauge issues - it's also for a 2015 Picasso, so possibly the fix wont apply to my Relay. But its certainly interesting, and although its long it is still live. One thing I note is the pressure gauge reading is a voltage and my battery has very low voltage - which might affect sensor output. But once it's running the votlage is OK so I think thats a red herring.
I'm pretty competent at general motor mechanics, changing EGR valves etc but my drive is on a slope and raising vehicle to work on it is tricky. I'm also not so flexible as I used to be!
Added to that, I dont have any diag kit for the Citroen. It would be really useful to know if its possible to reset the codes, especially the countdown to no start - and what is the least expensive product which will do this? Any thoughts on this please? I'll post again when codes read tomorrow.
PS thanks for modding the thread title!

[Tommohawk]

Hi again. Overnight I remembered I have an ELM27 reader, which I thought was specific to VW, but turns out it'll read Citroen codes. It showed some low voltage issues, likely related to old battery, and also P22A0 Nox sensor 2, bank 1 circuit low, confirmed. No other Adblue related codes.
I cleared this in the hope it might completely reset mileage countdown - it did clear the code but didnt reset. No surprise from what I've read.
I went to garage and guy with fancy Snapon diag tool couldnt find any DTCs. So presumably mine found/cleared all there was to find.
P22A0 seems to be sensor fault, so hopefully not pump or tank related. However it might be due to low voltage. I plan to replace the battery, cos I cant risk that muddling every thing, and then see if fault recurs. Problem is of course I'm counting down my miles to no start.
So what would be great is to find the least expensive tool which will reset Adblue components - if it cost say £300 I can resell after and recover most of my outlay.
BUT - which tool does the job?? Theres millions of them. Topdon and Launch seem to be OK, but impossible to know which version will do it. The Launch X431 looks OK .. but Pro version? Pro+? Pro Elite??
Can anyone offer some info on the please?

[Paul-R]

You need to go into a menu (probably in the engine/fuel ECU) where you have the option to reinitialise the NOx system. I'd just try the first one to hand. Can't help with which one otherwise.

[Tommohawk]

Ok Paul thanks for that. I'm just thinking I don't want to risk circa £250 on product that doesn't work.

[RichardW]

Topdon or Launch should be helpful - drop them a message to see which can do it. With most garages charging £100+ for a diag session these days, and the starting point for diagnosis almost always being a computer, £200 for a machine is a reasonable investment.

[Tommohawk]

Thanks Richard.. agree that it's worth it not least because I have a couple of longer trips planned in the campervan and don't want to get caught out with a "no start"
It's surprisingly difficult to extract the information from suppliers though, some of which are UK based but the Comms don't sound very local.
I've spent the last few days trying to investigate.. I say a YouTube clip featuring Launch 431 pro elite which demonstrates ability to do rest / reinitialise Adblue but when I contacted Launch via eBay they say it wouldn't do this.

[Tommohawk]

One step forward, two back.
I bought Topdon Artidiag 800BT2 ~£250. I checked the DTCs, and it couldnt find any - maybe no surprise as I'd cleared them with my cheapo reader. The NOX sensor reset function worked - it cleared the countdown to no-start which is terrific. Of course this hasn't actually repaired anything - I'm hoping the issue was a dodgy voltage from the sensor due to a failing main battery, which has now been replaced. Live data shows constant sensor reading of 20ppm which apparently is normal - doesnt kick in until temperature is ~200deg C... so I'll check that in a while.
Meantime, having replaced the battery, I did a BMS reset. And now I have 5 new fault codes which relate to comms with various components.
"Airbags and pretensioners ecu
DTC Description Status
U1703:86 Communication fault with the instrument panel
Intermittent
Built-in systems interface
DTC Description Status
U1703 Fault - absence of communication with the instrument panel ecu-Message invalid
Intermittent
U0019 Fault on the Comfort/Body CAN (CAN B)-No activity on the CAN
Intermittent
Audio-navigation system LTM
DTC Description Status
U0155:87 Communication with the instrument panel-Not characterised
Permanent
Instrument panel
DTC Description Status
Page 2U0019:88 CAN fault-CAN in error"
These faults may clear through re-learn, or may not. I can clear them but they recur immediately. I cant find any reset function.
At this point it probably makes sense to start a new thread, as this is now unrelated to Adblue.
Mods please - does that ake sense?

[Trickiedickie]

Hi. Not sure why you did the bsi reset but hopefully those codes should clear on their own or with your diags tool.

More important is the P22A0 Nox sensor 2, bank 1 error code. It is not reporting an issue with the adblue tank or with the adblue level. It is reporting the nox sensor fitted to the exhaust/dpf is having issues or is faulty. The fix is to fit a new nox sensor. The buy in cost is about £225 for a psa original part (recommended) or just under £100 for a lower quality copy part (risky). New replacement part probably needs coding after fitting.

[Tommohawk]

Thanks for that. I did BMS reset because I read that should be done following battery replacement, and the Topdon unit offers that function. Maybe that not correct information?
As you say the NOx sensor code relates specifically to the NOx sensor and a new sensor may well be required. However, because the system voltage was very low prior to battery replacement, it's possible this caused a sensor read error.. so my plan is to see if the error persists once it reaches operating temperature, and replace if required.