P2A00

[GORAX]

Hello everyone,

I get the message via Diagbox but the service light is not on. The check engine light doesn't come on either. My car was regenerated last week. There was a lot of white smoke with a smell of ammonia coming out of the exhaust for 1 hour. My engine is often at high speed. I think he is in regeneration more often. I found a nox probe replacement part but it was very expensive. Cheapest original is 240 euros. You can get them on Aliexpress for 80 euros but how good are they?

I have used google translate sorry.

[GiveMeABreak]

I think you are getting confused as you are talking about regeneration in one sentence and ammonia / NOx in another sentence. These are 2 different systems that have separate and independent functions.

The SCR (Selective Catalytic Reduction) system uses Adblue injected into the catalytic converter to treat and convert the NOx gases into water and then there is the Diesel particle filter system that captures the particulate matter and burns these off during regeneration. Eolys fluid is added to the fuel tank whenever you add diesel, and assisted regeneration by lowering the exhaust gas temperature required to regenerate the filter.

In the case of this specific fault (P2A00), it is referring to the Upstream NOx sensor, which may be loose and checks are required and to tighten it up if necessary

[GORAX]

Thank you! It's really difficult to find someone who will explain it to me like that. The NOX sensor doesn't have to be defective, it could just be loose or a cable problem?

What exactly is causing this ammonia and white smoke?

What do you think about the spare parts from China or from Aliexpress?

[GiveMeABreak]

Ok, so the Adblue is a UREA solution and the smell of ammonia is symptomatic of a leak of the adblue. So with this fault code, it is requesting a check of the upstream NOx sensor assembly to make sure it it tight and properly secured. If not, the adblue is at risk of leaking out onto the hot exhaust and will create the ammonia smell / vapour. Apart from this, you will very soon start to empty your Adblue tank and then you'll aave the added problem of the engine starting prohibition warning if it gets too low.

I wouldn't leave this too long to be honest, as you don't want to be topping up the Adblue tank all the time.

As for spare parts from Ali or China - I would not personally buy anything like this from those places. You may not even have to - it might be that the sensor needs checking and the assembly tightening up.

[GORAX]

Where can I find a construction print to see exactly where this sensor is located?

Is it normal for the service light or check engine light not to come on when there is a problem like this?

[GiveMeABreak]

Yes, not every fault results in an engine management warning lamp.

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[GORAX]

I have donate 10 Euro now. Is it okay?

[GORAX]

+ 2 euro

[GiveMeABreak]

Hi. Thanks for your Forum Donation.

Ok, so your vehicle is a Euro 5 emissions standard, so does not have all the additional sensors with later Euro 6.* vehicles, so please understand that there are sensors shown on the diagram that your vehicle does not have fitted.

Your vehicle only has 1 NOx sensor (downstream), so this is the one I suspect that needs to be checked.

The NOx sensor is shown at (8) and is part number: 9821120980, £416.80 inc. UK 20% VAT.

[GORAX]

Cool great! I'll take a look at it in the workshop next week and report back here.
According to the vehicle registration document, I have Euro6

[GiveMeABreak]

Hi

Yes this can be confusing as your engine (DW10FD) is a Euro 5 standard, but the overall vehicle is Euro 6.1. So it can be confusing, but as mentioned you don't have (7) Upstream NOx sensor or (12) Soot Sensor fitted to your vehicle.

[GORAX]

Thanks! I will report back after check

[GORAX]

Diagbox shows DPF is 38% full. Is this too much?

[GiveMeABreak]

Remember that this value will change and vary as the filter starts to fill up, then falls back after it regenerates.

[GORAX]

Remember that this value will change and vary as the filter starts to fill up, then falls back after it regenerates.

Ist this ok for now the 38 percent? I will give the DPF for wash and cleaning.