Risk Of Filter Blocking - Service Light On

[Luc]

Hello,

 

anybody know what that message mean "Risk of Filter Blocking" and service light ON, and how to fix it ?

I have this message for more than 400KM and engine is still working ok but I'd like to fix this and try to approximate the cost to be prepared.

 

car is C5-II from 2005, engine HDI 1.5, 110CP, 110.000KM.

 

thank you.

Luc

[kfk]

worth looking through these posts here

[Luc]

ok

 

I think it mean FAP filter exchanged ( cleaned/refurbished... ) and EOLYS fluid toped up.

I just have to find what's the cost of this operation here in Europe: Hungary or Romania... just hope the prices did not got to high in December. ;)

 

thank you

L.

 

 

p.s.

got a price from Citroen Romania for this operation:

Tube Press ~25 E

FAP Filter ( new ) ~ 900 E

Rubber gasket for FAP ~ 54 E

Aditive Eolys 5L dx42ci ~171 E

Work ~1-2h ~100E

total including vat:

~1250Euro :blink: :( :angry:

 

wow this is ~15% from actual value of the car on sh market... not sure if this really worth.

[Randombloke]

got a price from Citroen Romania for this operation:

Tube Press ~25 E

FAP Filter ( new ) ~ 900 E

Rubber gasket for FAP ~ 54 E

Aditive Eolys 5L dx42ci ~171 E

 

I had a FAP and the fluid done here in the UK (2.2 HDi 136).

 

Price for the FAP was £143.75, so about €200. Price for the fluid was £77.59, so about €110.

 

You need to look at going somewhere else for this service, but having said that, mine is a 2.2 not a 1.6.

 

kfk or iannez, any thoughts? Is the later 1.6 much more expensive than the earlier (Mk 1) 2.2?

[Luc]

I will go to Hungary next week at authorized Citroen Service to check there the cost, I hope will be cheaper.

[Luc]

Hello,

 

The prices I had did not match your prices, are much higher so I decided to try to clean the FAP myself.

If the operation will be successfully for the next 20.000-30.000km I will be very happy.

 

At this moment I removed the FAP filter, cleaned with water, and put the 2 gaskets in place ( I hope I remember correct how was the gaskets positioned ).

Tomorrow I will try to put it back on the car and I will let you know if I solved the problem.

 

http://i220.photobucket.com/albums/dd237/L_DM500s/DSCF2313s.jpg

 

http://i220.photobucket.com/albums/dd237/L_DM500s/DSCF2302s.jpg

 

 

regards

Luc.

[Luc]

Hello,

 

I have no luck after I cleaned the FAP filter ( cleaned with cold water for ~2 hours, sinked in water over night and in the morning again cleaned with water, hot and cold for ~3 hours, dried with pressure air at the end... ) I still get the message "Risk of filter blocking", I drive ~40km but still the same.

 

what's next ?

 

changing the FAP pressure sensor, code 1618Z9 ?

Anybody have a price for the code ?

 

 

thx

L.

[kfk]

i fear all your doing delaying the replacement of particle filter ......you have already answered your questions with previous posts.

 

If you think the sensors is faulty book it in with a dealer and get it confirmed......if you were right you will have saved the cost of the particle filter and hopefully have it fixed.

 

If your wrong and your told you need a particle filter, you will have saved the cost of the sensor and know where to go next.

 

Believe me, if there was a cheap answer to this i'd be sharing it with you.

[Luc]

ok thank you for your answer,

 

I tried to clean the FAP myself because I read that other people did it and they solved this problem and because I seen that also dealers replace the FAP with one refurbished not brand new, cleaned ( yes true, cleaned by factory ).

 

I was thinking that it is possible to be that sensor faulty because even I have this message for more than 800km I did not had any problem with the engine power/torque.

 

here are some pictures of the housing filter... can be seen the ash... ( I tried to clean with a vacuum cleaner and tissue )

 

http://i220.photobucket.com/albums/dd237/L_DM500s/DSCF2322s.jpg

 

http://i220.photobucket.com/albums/dd237/L_DM500s/DSCF2317s.jpg

 

http://i220.photobucket.com/albums/dd237/L_DM500s/DSCF2314s.jpg

 

http://i220.photobucket.com/albums/dd237/L_DM500s/DSCF2325s.jpg

 

regards

Luc

[Luc]

Hi,

 

After I found a very good documentation about FAP system and his management I decided to make an experiment and to modify the car to work whit out FAP filter.

 

Differential pressure sensor from FAP is the one that monitor the FAP filter state as it is explained in this doc:

 

The differential pressure sensor constantly measures the difference in pressure between the inlet and outlet of the

catalytic converter/anti-particle filter assembly.

This measurement makes it possible to determine the blockage level of the filter. The sensor consists of:

- an electronic circuit for amplifying the signal,

- a sensitive diaphragm.

The diaphragm is subjected on one side to the catalytic converter inlet pressure (upstream) and on the other side to

the filter outlet pressure (downstream).

The sensor provides a voltage proportional to the differential pressure measured by the diaphragm (?P = upstream

pressure - downstream pressure)

 

The particles trapped on the filter walls, together with the additive and the other residues, naturally increase the loss

of the load measured at the ends of the anti-particle filter during the course of its use.

The engine management node permanently checks:

- the state of the filter (by means of a "filter control" function),

- regeneration aid (by means of an "aid" function).

PARTICLE FILTER CONTROL FUNCTION

The role of the control function is to:

- determine the state of the filter (blockage level),

- determine, if necessary, the activation of the regeneration aid function,

- check the efficiency of the artificial regeneration.

The following information is used by the engine management node in this area:

- distance travelled,

- differential pressure value,

- exhaust gas temperature downstream of the catalytic converter,

- exhaust gas temperature upstream of the catalytic converter,

- total quantity of additive injected,

- intake air flow rate.

Determining the filter blockage level

The total quantity of particles, cerium oxide and various residues present in the filter cause a variation in the load loss

of the actual filter (the inlet pressure is different from the outlet pressure). This figure, constantly measured by the

pressure sensor, represents the filter blockage level.

The engine management node map includes six different operating areas, determined starting from the calculation of

the exhaust gas flow rate.

The exhaust gas flow rate is basically calculated using the following parameters:

- differential pressure,

- exhaust gas temperature downstream of the catalytic converter,

- intake air flow rate,

- atmospheric pressure.

Filter blockage level

The following graph illustrates the six different filter operating areas....

 

http://i220.photobucket.com/albums/dd237/L_DM500s/pressure.jpg

 

? P - differential pressure

c, intermediate zone

l/h, exhaust gas flow rate

d, partly blocked filter

a, perforated filter

e, blocked filter

b, regenerated filter

f, completely blocked filter

 

The areas from "a" to "f" represent the different filter states calculated by the engine management node.

Regeneration is designed to keep the filter within states "b" or "c" irrespective of the mileage covered or the driving

style.

The engine management node activates the forced regeneration in the following cases:

- when the differential pressure values go from zone "c" to "d",

- when the differential pressure values entre zone "e",

- when the differential pressure values enter zone "c" and the driving conditions are favourable for regeneration

(conditions in which regeneration will be faster).

Normal operating area from "b" to "d"

When moving from zone "c" towards zone "d" (more or less quickly depending on the driving conditions), the engine

management node makes a request for regeneration aid to return the differential pressure values to within zone "b"

or to zone "c" (depending on driving conditions).

Critical operating area: "e"

When regeneration is carried out in critical conditions or is interrupted, the quantity of particles stored by the filter is

only partly destroyed. Under these circumstances the filter may become too clogged, the difference in pressure at the

ends of the filter vary more rapidly; the engine management node detects that the filter is overloaded and signals this

by switching on the diagnostic warning light in the instrument panel.

In these conditions the engine management node implements a reduced fuel flow rate strategy which, as a result,

restricts the speed of the vehicle.

Abnormal operating areas: "a" and "f"

Zones "a" and "f" represent conditions in which the differential pressure is abnormal.

Zone "f" filter completely blocked: the differential pressure is constantly above 900 m/bar or above a level that varies

according to the exhaust gas flow rate. In this condition the engine management node signals that the filter is

overloaded by switching on the diagnostic warning light.

Zone "a" filter perforated: the differential pressure is below a certain level which is dependent on the flow rate. In this

condition the engine management node signals that the filter is perforated by switching on the diagnostic warning

light.

In these conditions the engine management node implements a reduced fuel flow rate strategy which, as a result,

restricts the speed of the vehicle.

Filter blockage development

During the combustion of the particles, the cerium oxide does not burn, but is deposited on the walls of the filter;

these deposits inevitably increase the load on the filter.

The graph below illustrates the gradually clogging of the anti-particle filter due to the accumulation of cerium oxide.

? P - differential pressure

c, intermediate zone

l/h, exhaust gas flow rate

d, partly blocked filter

a, perforated filter

e, blocked filter

b, regenerated filter

f, completely blocked filter

during normal operation the differential pressure measued at the anti-particle filter develops on the basis of the

quantity of cerium oxide accumulated, in other words it depends on the mileage of the vehicle.

...

This difference in pressure increases very quickly in proportion to the exhaust gas flow rate.

The capacity of the particle filter is calculated to ensure normal engine operation for 80,000 - 120,000 km (or 180,000

km starting from 12/2004).

Correction of the blockage level depending on the quantity of cerium oxide accumulated in the particle

filter.

A used anti-particle filter has a different loss of capacity compared with a new filter.

The graph below illustrates the affect of the presence of cerium oxide on the filter blockage level.

For the same flow rate Qv1, depending on whether the filter is new or has been used for 80,000 - 120,000 km (or

180,000 km starting from 12/2004), the parameter ?p will be different.

The move from the operating condition identified by point ax to the one identified by point ay is therefore no longer

due to the accumulation of particles in the filter, but to the amount of cerium oxide deposited on the anti-particle filter

walls.

In order to differentiate between the loss in capacity due to particles and that caused by cerium oxide, the engine

management node continuously adapts the blockage level maps according to the quantity of additives present in the

filter....

 

 

1) so the solution is to trick FAP computer to think that sensor report all the time the value from area b, regenerated filter.

How we can do this:

there are 3 wires that come to this sensor:

- Vcc 5V or any other constant value

- GND

- V from sensor to computer. ( I have 4.64V constant value no matter of speed and temperature of engine with that warning message )

 

we will cut the V wire and will insert a resistor from VCC to this line that will make the voltage to be constant all the time and will make the FAP computer to think that the value correspond for a regenerated filter ( we just invented 100% ecological fuel and Eolys additive for this car ).

 

The FAP filter will need to be replaced with a pipe or even easy will drill a big hole in blocked FAP core so exhaust gas and particle will go out easy.

 

2) to solve the Eolys additive low problem we can try to trick the low level sensor from additive injector or maybe to reroute the pipe from this injector in the additive tank so additive will not get low any more.

Or maybe just ignore it and filled with diesel when the message come on screen.

 

It is not possible to remove the whole FAP system because it is constant monitored by few computers and integrated in car ECM so the solution is to trick his sensors to think that all it is working OK.

 

p.s.

you can take the FAP documentation from here:

http://www.phones-direct.ro/public/FAP/

 

Luc.

[Luc]

Hi,

 

just fixed my problem:

 

1) checked the differential pressure displayed on Lexia in real time and the value displayed it was very low, in different engine rpm; this suggested a good FAP filter or a bad differential pressure sensor. Also checked the additive counters 1 and 2 with value displayed that FAP and additive inserted was for ~80.000km car have 115000km now... strange.

2) Changed the differential pressure sensor and the value was the same.

3) Checked the level on additive tank ( ~1/4 ) so I decide to make a full top up.

4) On Lexia reset to 0 the additive counters 1 and 2 ( 1 it is for FAP changed and 2 it is for additive fill up ) at additive computer.

 

result error disappeared, problem fixed without changing the FAP filter.

 

Luc

[eduk]

just fixed my problem:

 

Hi Luc,

Does that mean that you did not experiment with spoofing the sensor and removing the filter?

 

If I could find an old FAP to break up I would try it just to see if it works :huh:

 

Your link for information does not work.

http://www.phones-direct.ro/public/FAP/

 

I found another in Google, but not well detailed.

http://www.meca.org/galleries/default-file/Seguelong-rev.pdf

Page 15 shows different fuelling strategy during "regeneration".

 

Do you have any idea why your fault is now cleared? Sorry if you explained it, but I did not follow.

 

Do you know of any information about sensors? Sometimes you buy a new sensor and you have to fit it to test it. This can waste a lot a of time.

 

Regards,

Ed

[Luc]

Hi Luc,

Does that mean that you did not experiment with spoofing the sensor and removing the filter?

 

If I could find an old FAP to break up I would try it just to see if it works :huh:

Hi,

 

Yes not any more because I fixed my error resetting the computer and was no need yet to drill the FAP.

 

If I will have an old FAP then for sure I will try myself also. Just put an resistor and play with voltage from differential pressure sensor to computer to be ~4.2V

 

try here for doc:

http://www.phones-direct.ro/public/FAP/fap...51019135449.pdf

http://www.phones-direct.ro/public/FAP/fun...ve_function.pdf

http://www.phones-direct.ro/public/FAP/fap_system.pdf

 

Do you have any idea why your fault is now cleared?

 

Because in my case was only a computer bug, computer "know" that after the value of counter 1 and 2 it is time to change the FAP filter and looks like it don't care about the real state of the filter given by differential pressure if it is OK.

 

After the counter 1 & 2 from computer additive was reseted then error message disappeared, fault cleared because computer now think that I changed the FAP filter.

 

Do you know of any information about sensors? Sometimes you buy a new sensor and you have to fit it to test it. This can waste a lot a of time.

 

True now I have another differential pressure sensor in my garage... ~100E spent for nothing

 

regards

Luc.

[eduk]

Hi Luc,

Wow! That documentation is interesting and quite horrifying.

 

There are just too many thing to go wrong with this system.

 

What I mean is that it probably works only when all parts are working in specification.

 

For example suppose that the final silencer box became clogged.

 

Then the flow of gases would be restricted. Then the differential pressure across the FAP would be low, even when the FAP was clogged.

 

Horrible design.

 

Best regards,

Ed