Do it yourself
Frequently asked questions about cars and motorcycles

The P20E8 Error is Not Always Due to the AdBlue Tank

Model: (Various brands) Various
Part: AdBlue warning light

The classic AdBlue error is the infamous P20E8, which all diesel owners have come to know and fear. In many cases, this error indicating low urea pressure points to a problem with the tank, and most mechanics don't even open the bonnet, assuming that's the issue. Advise them to open the bonnet, as they might find some clues; it could be a sealing issue with the system. In the case of the vehicle in the video, the engine is completely sprayed with something that is neither oil nor water or mud: it is urea that has leaked from the system, and thus the ECU rightly flagged the error, but the tank had nothing to do with it: you would have spent a lot of money, and the problem would have remained.

Updated on 11 August 2026 by ScegliAuto

Video tutorial

Related tutorials

(Various brands) Various In this video, we see that the notorious error P20E8 is not always attributable to the AdBlue tank, and that it is not necessary to replace it as oft…
(Various brands) Various The video explains a common problem with Euro 6 diesel engines: the crystallisation of AdBlue within the injector and system. This phenomenon can cau…
(Various brands) Various The video shows what happens when AdBlue runs out in the tank and what to do to avoid unpleasant issues. When the AdBlue level in the tank starts to …

How to Open the Bonnet on the Lancia Y

To open the bonnet on this vehicle, follow these simple instructions: first, open the driver's door and locate the lever positioned just below the dashboard, marked with an image of the vehicle with the bonnet open. Pull this lever towards you until you hear a "click" indicating the bonnet is released. Next, exit the cabin and stand in front of the bonnet to disengage the safety catch and complete the opening. To do this, slightly lift the bonnet, locate the yellow lever underneath, and pull it to the left to fully release and open the bonnet.

Watch the video!


by ScegliAuto

More videos