Seeking advice re "Engine fault" message in Citroen Berlingo

PhotoMan

https://forums.moneysavingexpert.com/discussion/comment/81968465#Comment_81968465

And this won't harm to car in any other way, such as harming the gear box or anything? It just feels wrong to be doing it, although it obviously solved the issue.

ohreallƳ

I suspect your disappeared symptoms may be short lived. If the soot/ ash readings are on the limits, chances are the DPF will not regen due to safety reasons.

You may need to consider removing it and getting it cleaned professionally or replacing it.

Can you get a scan with the dpf soot readings?

sheslookinhot

https://forums.moneysavingexpert.com/discussion/comment/81968531#Comment_81968531

No damage will be caused.

James2k

https://forums.moneysavingexpert.com/discussion/comment/81968465#Comment_81968465

Lol..

PhotoMan

Original poster here. Not resolved yet.
The story so far - The error code P2002 (diesel particulate filter efficiency below threshold) came up on my Berlingo at the end of March.

I put some DPF cleaner into the diesel tank and drove for 15 miles on the motorway at 50mph in third gear then cancelled the code with my OBD2 code reader. I was then able to drive for several days with no error code but then the code recurred.

I took it to a local garage and they replaced the DPF pressure sensor in case the sensor was faulty. On collecting the car there was no error code. They advised me to to again do the drive for 15 miles on the motorway at 50mph in third gear which I did.

Unfortunately a couple of days later when I turned the engine on the error code returned. I telephoned the garage again. They seemed at a bit of a loss. I have booked the car back in for them to look at in a couple of days time.

Any advice or pointers gratefully received.

(Our code reader doesn't give any soot level readings)

paul_c123

There's different kinds of DPF cleaning. In order of cost/effectiveness, worst to best:

1. Simply doing a force regen
2. In-tank additive
3. On car, foaming DPF cleaner (needs some pipes disconnecting, then the cleaner connected and sprayed in, etc - a garage job).
4. Off car, send-the-DPF-away DPF cleaning service
5. Replacement DPF

I wouldn't even bother with step 2, I think its snake oil - anything which goes through the combustion cycle is going to be quite ineffective after that. Hence why professionals will try step 3 next.

tedted

Number 2 as, above remove top sensor inject cleaner in bursts and let it work.work.ive used mannol dpf cleaner which has worked well but others are available

Goudy

I wonder if this is due to adblue crystallisation.

Adblue is made up of around a third urea and two thirds deionised water and the water element is known to evaporate leaving the urea to crystallise.

Adblue quaility can be hit and miss and light use tends to mean using less, which allows more evaporation as it sits in the tank.

The P2002 is just the exhaust pressure sensor complaining and it's true that a blocked DPF will do that but any sort of blockage that effects the exhaust pressure will also cause it to flag.

The SCR system is post DPF, so if that's clogged with crystals, that'll certainly cause an adverse pressure reading at the DPF which is before the SCR.

It's quite common on certain engines like this. I seem to think Ford used this engine and it's common with those too.

There are some crystal cleaning products from Wynn and Forte that might help, but it depends on how bad it it.

Mildly_Miffed

Seconded that this is very likely your typical modern diesel low-use, light-use issue.

DPFs need to have the exhaust properly hot in order for the regeneration to begin. That involves giving the car some actual load, working it hard. Not just a nominal bimble down the motorway in a slightly lower gear. If the DPF hasn't had the change to regenerate for some time, it may need a longer regen in order to be properly cleaned, or it may need a workshop to set a manual regeneration cycle going.

AdBlue is injected periodically, and if it sits in the tank too long, it "goes off" and crystallises, blocking the injector nozzle.

Modern diesels really are not suited to low mileage or light bimbling use.
DPFs have been on diesels for at least a decade and a half - Euro5 emissions, removing soot and smoke from exhaust.
AdBlue/SCR has been on diesels for at least a decade - Euro6 emissions, removing NOx from exhaust, required for Low Emission Zones.
Modern diesel emission kit does a fantastic job of removing some seriously nasty pollutants that kill lots of people, especially in urban areas, but you do need to be aware of these factors when choosing an appropriate car.

born_again

I took it to a local garage and they replaced the DPF pressure sensor in case the sensor was faulty.

Find another garage, let them see car with the fault code. A decent garage should be able to sort it.

Adblue only has a short shelf life, even in sealed containers.