Cleaning clogged DPF on Ford Focus II 1.6 TDCI

[Sinclair]

It is known that the diesel engine is highly economical, and in the presence of the diesel particulate filter is also ecological. Unfortunately, like any filter, diesel particulate filter (DPF) can clog up. On the vehicle Ford Focus, as well as on other models was implemented scheme of automatic periodic burning of the accumulated soot in the filter. The engine control module monitors the changes in the differential pressure of the exhaust gases in the filter indirectly assessing the degree of filter clogging, and when it reaches a certain threshold, a regeneration cycle starts. During regeneration cycle the exhaust temperature increases up to above 500°C, at which the accumulated soot is burning, leaving a much smaller amount of non-combustible ash. Sooner or later, the filter will be filled with ash. Ford recommends the replacing the diesel particulate filter to a new one at 120000 km. When owner finds out the price of a new filter, his mood deteriorates significantly. In fact, the speed of particulate filter ash clogging depends on many factors such as the quality of the fuel and oil, good condition of fuel system components, as well as the nature of vehicle operation. Long high speed trips extend filter life, but short slow ones significantly reduce it. Sometime the engine control module determines that the filter is clogged with ash. In this case, the fault indicator illuminates, and the PCM story fault code P242F - Clogging the diesel particle filter - the accumulation of ash. The car will be in the mode of LOS. In fact, the filter may still be particularly filled with soot, which is not burned out by repeated unsuccessful attempts of regeneration. Optimal for the regeneration is a continuous movement of the car at speeds of over 100km/h. If the car is regularly used for short trips at low speed, the exhaust gas temperature does not reach the optimum value and regeneration will be not completed. Then you can try to do static regeneration. This feature is available in FORScan. However, in some cases, the engine control module refuses to start of static regeneration (probably, considering that the filter is clogged with ash and it did not help). I happened to meet the fault code P242F paired with P2458 (duration of regeneration of the diesel particulate filter) three years ago at 76000km mileage. Unfortunately, at that period there was not so remarkable program as FORScan, and I did not fullfil more detailed diagnosis. I had to go to Ford's company service. They offered to try a static regeneration. I left my car, and when I came to pick up, I received a bill for the replacement of the EGR valve + static regeneration. However, they additionally updated the firmware of the control module. Unfortunately I do not know if the EGR valve was indeed faulty. It is known, that this is a common cause, but no fault codes associated with the EGR was found in memory, and the car was mainly used for short trips. In fact, the filter may still be partially filled with soot, which is not burned out by repeated unsuccessful attempts to regenerate. Unfortunately, a few months ago the problem was repeated with the same error code with mileage of 97000km. This time I become a possibility to use the program FORScan and analyze data from several sensors. According to oscillograms, the EGR valve looked to be OK, and the differential pressure in the DPF exceeded 16kPa at speed 90km/h. It is clear that the absolute values of pressure at different cars may vary, but the engine control module compares first ones with the gauge recorded at the beginning of operation. I attempted to carry out a static regeneration using FORScan. Unfortunately, the engine control module refused to start the regeneration cycle, probably assuming that the filter completely clogged by ash and regeneration is not possible. Then I tried to reset the fault code and to carry out the passive regeneration on the highway. It should be noted that the fault code P242F can not be easy erased. The solution was found in a German forum. The advice was the following: "Pull the plug of the air flow sensor, and then start the engine again, stop the engine, read again the fault codes from memory ..... Now you find 2 additional errors from the MAF sensor. Reconnect plug of the MAF sensor and clear the fault memory ...... now it is possible to erase the P242F together with 2 MAF errors, and the display will not more indicate the engine management system failure." Indeed, the trick with disconnecting of the MAF plug (mass air flow sensor) allowed me to erase the fault code P242F, turn off the fault indication on the dashboard and exit the LOS mode. However, an attempt to carry out the passive regeneration on the highway also failed. Once the vehicle speed exceeds 100 km/h, and the differential pressure in the DPF exceeds 15kPa, PCM showed again the fault code P242F and car activated the LOS mode. Then I have tried to reset the diesel particulate filter learned values using FORScan. The procedure has passed successful, but the fault code P242F was not erased and the system remained in the LOS mode. The procedure has reseted parameters DIST_REGEN and DIS_ASHFULL to 1km and 99999km, respectively. I repeated the trick with a MAF plug, again erased all fault codes and tried to drive a few kilometers. Again, at 100 km/h PCM showed the fault code P242F and the car activated the LOS mode. Then it was decided try to demount the filter and wash it with water. In various forums you can find information about the successful experience of such operations. I should note that the demounting of the filter requires strong nerves, durable tool and one assistant. The most difficult in my case was to unscrew "welded" nuts holding the DPF on the exhaust bellows. Nuts are looking up, and there is very little space. I had to remove the grille under the "wipers" and operated from the top, using two extensions and universal joint for socket wrench plus long tube to create a leverage. Demounted filter was carefully washed with water from a garden hose. In flowing water were observed two factions - black and red (probably soot and ash). It was also noted that at the end of the washing operation the water began to pass through the filter much easier. However, it is almost impossible to remove all excess water from the filter. Therefore, after you install the filter in the car, water must be evaporated. In my case at first the differential pressure jumped up to 10 kPa at idle. However, as expected, the reason for this was the remaining water in the filter. After a short slow trip (see. Graph) the water has completely evaporated from the filter and the pressure has fallen sharply.

image001.png (121 KiB) Viewed 194937 times

I have repeated the trick with a MAF plug and erased all fault codes using FORScan again. Then I once more reseted the diesel particulate filter learned values using FORScan. Subsequent test drive at speeds up to 120 km/h showed a maximum differential pressure of up to 4 kPa. Considering that before washing already at 90 km/h, the pressure reached 16 kPa, then the result is positive. At the time of this writing, the car went after DPF washing about 1800km with an almost continuous sensors data logging. During this time, the car executed 7 regeneration cycles. Differential pressure during this period did not exceed 6.5 kPa (65 hPa) at speeds up to 140km/h. The data showed that the engine control module often starts the regeneration at the most inopportune moment while driving in the city or before the end of the trip. This leads to a significant reduction mileage until the next regeneration (see. Graph).

image003.png (93.15 KiB) Viewed 194937 times

I would be glad if the experience described here can help to solve the similar problems.

[drschlaumeier]

Hallo Sinclair,

thanks for the report.
Let me add some more findings which I experienced with my Mazda6 GY, Facelift, 180.000km

BUT FIRST: Thanks to the Forescan team for the great free program. I'm using it since a couple of month and it saved my life (car) several times.

In short, I had a very odd problem with my Mazda 6. During driving on highway it suddently (after 10-15 min) it went into reduced power mode. No error code. After waiting 2-3 min in idle mode it went everything ok. The problem was repeated several times during 500km highway driving. Later I discovered an error code P0104 MAF intermitted error.
So, the ECU tells me that something is wrong with the mass air flow.

Using Forscan showed me that MAF seems to be ok. My next try was to find some air leaks in the pipes but no success.
Ok, reading through some other forums the EGR could be the cause when sudden power loss. I disassembled the EGR and cleaned it but the problem still remained.
Also the live data of EGR seem to be ok. The only thing I could see is that EGR closes completely some seconds/minutes before problem occurs.
Next idea was the turbo. I checked vacuum and the mechanics but all seemed to be ok.
Meanwhile I also had the problem with P2458 but static regeneration worked fine. Mazda 6 did start the long regen procedure which was nearly 1h. I did it again and than the short procedure was started ~20min. so DPF is clean now. seems that because of reduced power the dynamic regen did not finish properly.

However, I ended up disabling the EGR by placing a metal plate into the EGR pipe.
Now everything worked fine. no problem anymore ... however, I had another error saying EGR insufficient flow after ~500km. But I expected this one.
So, the problem is/was the EGR.

I disassembled the EGR again and because I have an electrical EGR i also removed the DC motor from the EGR mechanics. And now I could see the problem:
The EGR valve mechanics moved but was a bit sticky but not fully. I suppose that during highway driving the EGR stuck in a certain moment when closing but after some seconds/minutes it closed. Therefore ECU sees some odd MAF values but could not associate to EGR. I disassembled and cleaned the complete mechanics of EGR and now everything works fine.

Remarks:
1. DPF Regeneration is > 600 degree at Mazda 6
2. if you have electric EGR than live data only show you the position of the DC motor but not the valve mechanics. If EGR valve is sticky and stays open you cannot see with live data. Either EGR stays always open than error EGR excessive flow will appear or, like it happened to me, if EGR sticks some seconds/minutes than MAF error will appear.
3. Static regen works with P2458 (until 140% soot in DPF) but according to manual not working when P242F (> 140% soot in DPF)
5. when P242F then disassemble and clean DPF. Afterwards start DPF Reset and DPF Assesment with Forscan.
4. normal regen cycle is every 100-200km and takes ~20-25km

Hope it helps other

Rgds

[wifiuk]

I have joined this forum to see if DPF clearing trick works, your information looks great...

I just want to get rid of the codes before i map out the DPF

[wifiuk]

just for future reference i tried the clearing the DPF and limp mode by doing the MAF trick and it worked.

Using forsan it even let me do a static regen ( ther regen didn't help me but thats a different story )..... excellent tip and very helpful.

Now have DPF mapped out of ECU

[jimopoulos]

I did a test and surpassed 28 dp-dpf,kpa 4000\min with my car is 120000km . that I'm a marked step before p242f. so far the car has not send any harm. what options do I have after .. on average range in 6.5-7.0 liters..................
sorry language but uses translate google

[jimopoulos]

just for future reference i tried the clearing the DPF and limp mode by doing the MAF trick and it worked.

Using forsan it even let me do a static regen ( ther regen didn't help me but thats a different story )..... excellent tip and very helpful.

Now have DPF mapped out of ECU

you have programm DPF mapped out of ECU
what program you used

[donate]

Thanks Sinclair for the explanation. I found it very useful, as i can compare your graphs with mine.

[rplc1976]

Hi

When I do a static regen on my Kuga, it says it is processing but the engine revs don't change! Should the revs not increase to heat up the DPF?

Thanks

[stefano375]

Hi to all,
even to me happened to find fault code P242F paired with P2458, i have used android torque pro with ELM327. I was able to clean P2458 but not P242F
I tried to clean this error while driving and it worked
For me was enough to drive at around 95 km/h and to send clean ECU errors with android torque pro and it worked
my car immediately exit from LOS mode and engine system fault message disappeared.
I hope that this can help to someone and I think that this "strange" method can be tested even with FORscan, obviously if you deem it appropriate

[EllwoodJT]

Hi I'm having a problem running the static regeneration part of the software. I can get pretty much all functions but it won't do a test on demand with the engine running but more importantly it won't let me do a static regeneration of the particulate filter, it says 'service procedure stopped, contact the developer'.... Is this a function that only comes with a paid version? I'm using Windows 7 and an Elm 327 cable off eBay. Ford focus 1.6 duratorq 2009. I've recently re filled the additive tank and changed the fuel and air filters. Thank you in advance. Ellwood