What is P2002 fault code?

P2002 fault code will usually display as “P2002 Diesel particulate filter (bank 1) efficiency below threshold.”

What does P2002 fault
code mean?

Essentially it means that your Diesel Particulate Filter has accumulated too much soot and ash, and occurs almost exclusively when it cannot regenerate itself and therefore logs the error.

If you’re unsure of how the DPF Filter system works, check out our full blog here:

How to Fix P2002 fault code:

This is very much dependent on the car you have and specifically how the sensors and regeneration systems work on your particular car, but there are some generic things that you should know.
A DPF should be able to regenerate on its own:

In a great working system, a DPF should be able to regenerate itself. You’ll only experience these issues when either the engine is now inefficient (and producing too much soot even during regeneration) or you’ve had some sort of contamination resulting in ash build up (cannot be burnt off in a regeneration process.

SO – until you’ve found your root cause, there’s no real point in spending money on the DPF.

Deeper understanding of your system!
The ECU cannot physically tell the situation with the DPF. Therefore it uses a range of sensors to establish an idea of what is happening. This fault code is almost always

If you keep experiencing issues with the DPF, the unfortunate reality is that you’ve probably not correctly diagnosed the root cause of the DPF build up, causing it to build up once again.


As always, if you need specific help, the guys from Diesel Laptops are awesome (jump on their train if you haven’t already).


If you need cleaning, talk to the friendly team DPF Cleaning / DCARB 877 573 2272.


If you’re looking for a new filter, check these guys out at DPFParts.com



Diesel oxidation catalyst