Adblue problem - 2015 C4 picasso II B78

[matthewpjgrant]

Aloha!
So this week has been a very unfortunate one for VIN VF7**************[VIN obfuscated, can be read by forum staff]! After a few weeks up in Scotland I came home to an "Electrical fault: have the vehicle repaired". Obviously on a 2015 I've seen this appears many many times and it usually clears itself up soon enough. However this time was different.

After day 3 I was out and about and I then got an "engine fault: have the vehicle repaired" followed immediately by "UREA emissions control fault".

After trying a BSI reset there was a plethora of faults so on went the diagbox. One fault caught my eye: "B1724 73 : Supplies protection and management relay stuck open". Proved by having continuity through both halves of the fuses. £250 on a new unit and a relatively easy swap later and fault code free! Excellent!

Until! First road test where we get up to temp.
Get the code "P20e8" : UREA Pressure Too Low"

I've had the adblue injector off and it was remarkably clean, have it a quick spray just incase and tested it's operation on diagbox. All fine as buzzing heard and fine mist of left over cleaner expelled. Left the injector out of the exhaust for now to see if any adblue comes out. I'm further tests

Next steps on diagbox:
Repair } Engine management } actuator test } test of the emissions control circuit}

"Check the effectiveness of the denox system" test finished: failure of the urea injector followed by the engine fault code popping back up. But know it's not the injector!

"Denox system relay control test" I can't hear a relay operating. Should this be from the boot or elsewhere?

"Check of the bleeding of the denox system" test in progress for about 30 seconds but I don't notice anything else happening around the vehicle

"Check of the denox system flow" test in progress then "activatin ended" but again nothing physical happens

"Check of the pressurisation of the denox system" problem encountered during the execution of the test. Test not started / bad pressure"

I've got the dnox system information here. Shows 4 bar but I've read that is the minimum it will display

Now I'm thinking either the pump, pressure switch or the ECU (leaning towards this given the other electoral fault) are kaput. I noticed Stuart W posted a very helpful thread I'm going to follow this when I've got a chance and see what other bits I can investigate as I won't drop a grand on a new tank without doing some investigation!
viewtopic.php?f=3&t=81429&p=792576#p792576


But herein lies my problem : Time!
It couldn't have happened at a worst time, I've got over 850miles to cover for work over the next 8 days starting tomorrow morning! And I'm dreading the "starting prevented in 750 miles" message I see that everyone gets with this type of problem.

Poking about of diagbox I found
"Repair } BSI } manual configuration } engine } presence of a Nitrogen oxide reduction unit" this is currently set to "yes" but *hypothetically* if this was set to "no" and the command *hypothetically* issued to the BSI what would the *hypothetical* outcome be?

A huge thank you to all in advance and I'll keep everyone posted with any solutions, even if it involves cutting the tank open and melting it back together

[RichardW]

You can re-initialise the Denox system which will give another 700 miles till no start. If you can't hear the pump running when it should do the pressurisation step then odds on it's broken. This means new tank time...but it may be possible to get it open and if the Urea has not leaked into the pump section you might be able to fit another pump. Someone here did a pressure sensor bypass but that doesn't sound like your issue.

[wheeler]

I've had the adblue injector off and it was remarkably clean, have it a quick spray just incase and tested it's operation on diagbox. All fine as buzzing heard and fine mist of left over cleaner expelled. Left the injector out of the exhaust for now to see if any adblue comes out. I'm further tests

Next steps on diagbox:
Repair } Engine management } actuator test } test of the emissions control circuit}

"Check the effectiveness of the denox system" test finished: failure of the urea injector followed by the engine fault code popping back up. But know it's not the injector!

Just because there is some urea mist coming out the injector does not necessarily mean its not faulty. There is a proper test of the injector when you do the guided test process where the injector is removed & temporarily pointed into a measuring cylinder, the pump & injector are then operated for a set amount of time (around 2-3 minutes from memory) & at the end of the process it tells you how many ml of urea should be in the measuring bottle.

[matthewpjgrant]

You can re-initialise the Denox system which will give another 700 miles till no start. If you can't hear the pump running when it should do the pressurisation step then odds on it's broken. This means new tank time...but it may be possible to get it open and if the Urea has not leaked into the pump section you might be able to fit another pump. Someone here did a pressure sensor bypass but that doesn't sound like your issue.

That's good to know! I'll have to make sure I take my diagbox laptop and an extension reel with me then (the battery in its knackered) how many times can this be done? Might just be cheaper and easier to get a new laptop battery

I can't hear the pump but I also can't hear the system control relay. I'm really hoping it's a loose connector but I'm imagining it's going to be the worst case scenario and it'll be the PCB and there's no Amazon special that's going to help me there (like it would for the pressure sensor and maybe the pump)

[GiveMeABreak]

Have you actually refilled the UREA tank?

[Paul-R]

I wouldn't say that the number of times is limitless as sooner or later something else will go wrong but a fair few times at least. You may find that not only does the countdown disappear but you will get several hundred miles before the MIL illuminates and the countdown starts again.

[matthewpjgrant]

!

Just because there is some urea mist coming out the injector does not necessarily mean its not faulty. There is a proper test of the injector when you do the guided test process where the injector is removed & temporarily pointed into a measuring cylinder, the pump & injector are then operated for a set amount of time (around 2-3 minutes from memory) & at the end of the process it tells you how many ml of urea should be in the measuring bottle.

I tried the actuator test and the injector is the only component that at least had some operation to it. Tried the full guided test but unfortunately nothing came out of the injector and I suspect that's because the pump, the PCB, the wiring harness or the pressure sensor has a fault that prevented the injector from operating.

I'm guessing I should at least be able to hear the pump trying first? (I've never really noticed if can hear it before under normal driving conditions though)

[matthewpjgrant]

Have you actually refilled the UREA tank?

I can definitely see the level sitting about 1.5" below the top of the tank. Refilled it about 6 weeks ago making sure not to overfill it but that was following it getting down to around 200miles until the starting would be disabled maybe some crud sucked into the pump when the tank was low?

If memory serves it's only the 3rd or maybe 4th time I've done it (had the car at around 20k miles, now at 86k miles). Doesn't use anywhere near as much as the mrs' Kia!

[matthewpjgrant]

I wouldn't say that the number of times is limitless as sooner or later something else will go wrong but a fair few times at least. You may find that not only does the countdown disappear but you will get several hundred miles before the MIL illuminates and the countdown starts again.

Thank you! At least that gives me some wiggle room until I've got the time to get back underneath and drop the tank out.
I'm curious if doing this would negate the need to worry about any other adblue bits going wrong? Repair } BSI } manual configuration } engine } presence of a Nitrogen oxide reduction unit" change from "yes" to "no" has anyone ever tried this? Is this all they'll do at those 'adblue delete' places?

[seefourpio]

Hi, I've just been hit with the dreaded Adblue Service lights and klaxons (UREA and Engine) also on a 2015 C4 Picasso II (Grand) B78 - and it looks as though I might have a couple of issues. The injector appears to be leaking and there are no communications with the UREA ECU. Errors were cleared but returned. The UREA service light did clear itself for a day or so - but then returned and has remained ever since.

I'm assuming, at this stage, that both will probably have to be replaced - but I'm wondering if I could make do with a salvaged tank (if it comes to that).

Would it be possible to get the part numbers for the UREA injector and tank? Am I right in thinking that these parts can be replaced and initialised with Diagbox - without needing "server" access?

VF7**************[VIN obfuscated, can be read by forum staff]

Thanks

[PaulC5]

A similar post with links to others to read viewtopic.php?t=86667

[seefourpio]

I hadn't spotted that. Thank you. That's great info in there!

[seefourpio]

Hi,

Would it be possible to confirm the part number for the AdBlue tank?

VF7**************[VIN obfuscated, can be read by forum staff] - 1.6 BlueHdi 2015

Diagbox is failing to communicate with the unit, so I'm assuming the PCB has failed and would like to try and source a salvaged replacement.

I think it's 9813676080 - but it would be great if this could be confirmed.

Many thanks,

Mark

[mickthemaverick]

We don't have access to the parts database at the moment I'm afraid Mark, we are trying to sort that out but not looking too hopeful at the moment. Your local dealer should be able to give you the part number based on your VIN if you call the Service/Parts dept. Good luck

[seefourpio]

Thanks for the info. That's a shame about the parts database access. Hope you're able to get it back at some point.

I tried my local dealer (to find the part #). The chap in the Parts department said he wasn't allowed to give out part numbers! But did provide the last four digits - which I think is enough to show what the new replacement units are at least.

Anyway, I think I'm confident enough to source a savlaged unit now. However, I'm keen to have a go at repairing my current first, if I can.

In Diagbox, I have no dialoge with the UREA tank/ecu. However, I am able to read the paramaters and run actuator tests etc via the Engine ECU. I can hear the pump and injector etc (which I also just replaced) but have the low pressue issue and am now assuming the pressue sensor is at fault and will look to repair it - as descibed in the link above. My only hesitation is the lack of "direct" comms to the UREA ECU, - is this normal or a fault? In the Diagbox global test, it doesn't error but is greyed out (with no dialogue) and dropped to the bottom of the list.

Thanks