Fap soot load 150 %

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

torneol
Posts: 18
Joined: 29 Jan 2021, 19:25
x 1

Fap soot load 150 %

Post by torneol »

I get that information from FAP application. How is it possible?

Is It cause of a faulty egr or something else?

Online
User avatar
GiveMeABreak
Forum Admin Team
Posts: 22630
Joined: 15 Sep 2015, 19:38
x 2342

Re: Fap soot load 150 %

Post by GiveMeABreak »

It would seem to indicate your DPF is full. You need to look at the engine ECU data - specifically the information relating to the particle filter and regeneration. If you can screenshot that, then post it here it may help.

torneol
Posts: 18
Joined: 29 Jan 2021, 19:25
x 1

Re: Fap soot load 150 %

Post by torneol »

Thanks for reply! Car is going to service tomorrow, cause I dont have Diagbox, at least not yet.

I'll write a report here about the conclusion after the serviceman has check whats wrong with the car.

There have been doubts about weak battery. There are warninglights at dashboard, which are telling about problems with abs, asr and handbrake. I have bought a new battery today, so atleast that promlem is sorted. There were also several times economy mode and it keep coming, even I recharged the battery properly.

Now somebody think, that probably a faulty egr might give those errors. I find next text from this forum, I suppose:

For some reason when they programmed this, the fault with the EGR valve does not put the engine fault light on, but it does interrupt the engine signal to the ABS / ESP ECU which then gets upset and puts the handbrake light on. Genius. I chased this for about 6 months before changing the EGR valve which finally fixed it :? Changing the valve is not as hard as it looks - access is not too bad with the wipers / scuttle etc removed.

So tomorrow we'll see, if it som wheel sensor or maybe that egr. Is It possible, that faulty egr doesn't start dpf burning?

torneol
Posts: 18
Joined: 29 Jan 2021, 19:25
x 1

Re: Fap soot load 150 %

Post by torneol »

And fore information, FAP app. shows, that cinder count in fap is 85% and fap life left is another 17500 kms.

Online
User avatar
GiveMeABreak
Forum Admin Team
Posts: 22630
Joined: 15 Sep 2015, 19:38
x 2342

Re: Fap soot load 150 %

Post by GiveMeABreak »

So probably getting towards end of its life - 13 years is not bad....

torneol
Posts: 18
Joined: 29 Jan 2021, 19:25
x 1

Re: Fap soot load 150 %

Post by torneol »

But there is no warning lights in dashboard. I think, that it should give me a warning about getting stuck. Maybe it's on a way :-D.

It might be better not to watch FAP applications information, maybe it need just driving...

Is it a proper way to fix that fap, if service make forced fap burning at garage? Or do I have to buy a replace one...

Online
User avatar
GiveMeABreak
Forum Admin Team
Posts: 22630
Joined: 15 Sep 2015, 19:38
x 2342

Re: Fap soot load 150 %

Post by GiveMeABreak »

Don't forget that depending on what reading you are looking at on your App, soot accumulates in the filter until the next regeneration takes place. So the clogging is only showing as a % at the time you look at the reading - after regeneration takes place it will fall back again.

Yes you will get a warning if the filter is starting to clog. That is when you need to go for a decent drive with the engine warm to allow it to regenerate out of traffic.

It's the Additive (Cerine) that is dumped into the filter that accumulates over time that cannot be burned off, along with oil and engine deposits and the ash that lead to eventual blocking of the particle filter.

torneol
Posts: 18
Joined: 29 Jan 2021, 19:25
x 1

Re: Fap soot load 150 %

Post by torneol »

There were no faultcodes in ecu. I have watch several times from app, if egr is working. Sometimes it gives deacent readings, but mostly it shows 0%. So probably the egr or its contact is faulty.

After I drive home, I take egr electric connector off and try to wigggle it a bit few times. No result, egr shows still 0 %. Finally I get a faultcode, P0406. Which indicates, that egr has some problems.

At thursday it goes back to service. They try to find out, whats wrong with that. If they find a faulty egr, the will replace it and then they try forced burning to dpf. Hopefully they can solve all problems.

Is it so, that dpf burn does take action, if egr is faulty?

Online
User avatar
GiveMeABreak
Forum Admin Team
Posts: 22630
Joined: 15 Sep 2015, 19:38
x 2342

Re: Fap soot load 150 %

Post by GiveMeABreak »

The EGR does not operate all the time remember. It is only used as and when needed and commanded by the engine ECU so you won't get a reading all the time - especially when it is closed (not supplied).

The DPF regeneration is decided on by the engine ECU,
The EGR's main role is to reduce NOx gases by redirecting some of the exhaust gas back into the cylinders to lower the combustion temperature.

torneol
Posts: 18
Joined: 29 Jan 2021, 19:25
x 1

Re: Fap soot load 150 %

Post by torneol »

Yeah; I know, how egr works. However, it seems a bit odd, that sometimes egr works well (some reading other than zero) and suddenly nothing. Revs are same and no other sircumstance dosent change at all.

For example, driving along the flat road, speed about 60 km/h, rev about 1720 rpm and egr 38 %, fap pressure 11 mbar . After few sec. it's rev about 1640 and egr 0 %, FAP pressure 31. Rev 1940 and egr 0 %, FAP pressure 41.

When idling, situation is the same. Sometimes egr gives some number (ex. 38%), sometimes nothing (0 %) . Idle rev 750 rpm, FAP pressure 1...6 %.

Online
User avatar
GiveMeABreak
Forum Admin Team
Posts: 22630
Joined: 15 Sep 2015, 19:38
x 2342

Re: Fap soot load 150 %

Post by GiveMeABreak »

The EGR has a testing procedure to determine degree of the valve 'sticking' which is the noise you can hear sometimes when switching the engine off. If the EGR valve is jamming you should be able to see this on the live parameters. There is a reference value shown in Diagbox when testing that you can compare the EGR % opening to. If there is a discrepancy of 35% or more between the reading and the reference value then you will have a P0488 code.

torneol
Posts: 18
Joined: 29 Jan 2021, 19:25
x 1

Re: Fap soot load 150 %

Post by torneol »

Ok, thanks for that info.

What about that P0406, which I get? What does it mean? I have understand, that with that code, egr have connections dificulties, it might be broken or something like that.

Online
User avatar
GiveMeABreak
Forum Admin Team
Posts: 22630
Joined: 15 Sep 2015, 19:38
x 2342

Re: Fap soot load 150 %

Post by GiveMeABreak »

P0406 is the EGR valve position copy signal: Copy voltage too high.

When you have this fault, it goes into backup mode and the engine ECU cuts regulation of the EGR, which will show on the parameter measurements in Diagbox as:

OCR controlling the electric EGR valve = 0 %
Position repeat = 0 %

Suspect areas are: Engine ECU 5V shared supply, Electrical harness, EGR valve.

The fault may come and go, but the engine management light will only come back on after 3 engine start cycles:

A Starting Cycle is:
  • Engine start
  • Engine cut-off
  • Wait for the instrument panel to switch off

torneol
Posts: 18
Joined: 29 Jan 2021, 19:25
x 1

Re: Fap soot load 150 %

Post by torneol »

Hmm, now I dont understand. Meaning, that egr is faulty and have to replace? Or something else?

Online
User avatar
GiveMeABreak
Forum Admin Team
Posts: 22630
Joined: 15 Sep 2015, 19:38
x 2342

Re: Fap soot load 150 %

Post by GiveMeABreak »

This is the fault description for the code you said you had (P0406). So the sensor is getting too high a voltage and the engine ECU is putting into backup mode as described above.

It really needs the electrical circuit checking first of all: Engine ECU 5V shared supply, Electrical harness or the actual EGR valve itself. Check all the connectors to the EGR and the wiring - make sure there is no short. This 5V shared circuit is tested using a terminal box. It's best to check the electrical circuit first before replacing the EGR valve as replacing it with a new one may not make any difference if the fault is in the electrical circuit.