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Diesel Particulate Filter (DPF) dash light

42K views 25 replies 13 participants last post by  ludwigsburg1971 
#1 ·
Driving to work last night and the DPF light on the dash started blinking. As the car is 8 weeks old and just hit 5,000 K's it was a concern especially as most of the travel I do is at speed and should keep the filter clear.

According to the book the light may come on solid (ie not flashing) if the car is run very sedately or on short trips for extended periods of time and the filter does not reach a high enough temperature for the filter to burn off the collected particles.

If the car is left without the remedial action for an extended period then the light may start to flash as mine was indicating dealer action is required. The light had never come on solid at any time previously so going straight to the blinking stage was a concern.

I tried the 20 minute run specified to clear the solid non flashing light but with no luck. Light was still flashing away. I called the dealer (Canberra Subaru at Fyshwick) when they opened at 07:30 and they said drop the car in at 09:30 when I finished work. Very happy with their level of service as apparently they were busy.

They checked it out and apparently there is a bulletin out from Subaru Australia advising of the issue which is someting called "oil dilution". The fix is to drain the oil (I assume it was engine oil) and reset the DPF sensor. All up a 15 to 20 minute job that was done for free.

May be of interest to the other 2.0DT owners in Oz and congrats to Canberra Subaru for the quick fix.


Norm.
 
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#2 ·
They checked it out and apparently there is a bulletin out from Subaru Australia advising of the issue which is someting called "oil dilution". The fix is to drain the oil (I assume it was engine oil) and reset the DPF sensor. All up a 15 to 20 minute job that was done for free.

Norm.
Hi, have you had further issues in regards to this?
I own a 15 Outback I purchased in Oct 15, and have had the issue every 6-10 weeks and it's starting to irritate me a little... especially because I've moved away from where I purchased my vehicle and the new Subaru place down the road tries to charge me for it every time.
 
#3 ·
Same problem here. Oil level goes up until the oil dilution fault code will be generated. Have been monitoring the DPF burn process with OBD and Torque. The process takes place every 100 km-s, on other cars (Volvo, VW) it normally regenerates after 600-1000km-s.
 
#6 ·
Strange... I havent seen that light. Too much oil filled?


According to torque, mine has done 25 regens and i have over 17tkms now.


I cant notice regeneration when im driving, so i had to get torque to see it and there was 22 already.
 
#12 ·
I see from the dipstick that the dilution exists and think that the real problem is related to egr and DPF warmup injections. If one car has 2015 software and has done 25 regent and other has 2016 software and has done 100 regens, then it clearly shows that something is wrong.
 
#16 ·
Bit of an update.

So, I've been having the DPF warning light flash (apparently means oil dilution reached 10% or more) every 2 months or so all this time, and the dealer's been great in clearing it and changing the oil. But I have identified that the DPF Active Regen has been kicking in every 160-200km, causing the oil dilution to occur.
I am currently logging a few parameters to try and identify the issue, but god knows...
 
#17 ·
I drive now short trips more and it is winter, my car also makes regens more often.
Dilution is about 9%, it has been 10% also but no light yet...




So they clear dilution ratio to zero when oils has changed?
I do not know did they reset mine at first service at 15kms. :confused:
So just one oil change done, and i did not have obd tool then.
 
#18 ·
Yes, they are clearing the oil dilution every time.
It is really bizarre, but every one or two active regen it does, oil dilution will climb 1%... so at that rate, 6-10 weeks for the oil dilution to get to 10%, and the DPF warning flashes. According to Subaru, this is not an isolated incident, but they will not give me any more answers.

I am currently logging:-
DPF Regen Switch
Estimated DPF temp
Estimated Catalyst Temp
Pressure difference between DPF input and output
EGR Target angle
EGR valve angle
Running distance since last DPF regen
Intake manifold pressure
Boost
Engine RPM
Coolant Temp
Fuel rail pressure
Exhaust gas pressure
Final injection amount
and a few more things I can't remember to try and work out what is going on.
This is getting a little bit painful.
 
#20 ·
Yes, I found the PID with some help from Subaru Diesel Crew.
The most useful one, was "oil dilution 2", which is PID 221155 Equation 10-A/15, which gives oil dilution to one decimal, as opposed to the original oil dilution PID, which only gives whole numbers.
I have been monitoring the soot levels, oil dilution levels and active regen very closely, and it appears that NOx passive regen is not happening as often as I'd want it to.
I'm keeping an eye out on soot level rising and falling while not in active regen, and assume that soot falling without the active regen ON, means passive regen is occurring.
I have been heavily modifying my driving style to promote more passive regen to happen, and avoid (where I can) situations where soot rises rapidly.
I have changed things around a bit since 10 weeks ago, and now my oil dilution is only 7.8%, as previously, it would have hit 10% and triggered the warning light by now.

So far, I have found that passive regen (soot going down without active regen) can be relatively easy to trigger in:
-Going up a steep hill in 1st or 2nd gear. For some strange reason, it seem to occur more when engine is cold.
-Traveling on a flat road at approximately 60km/h in 3rd.
-Upon acceleration in 1st and 2nd gears. Particularly more successful when it is a sustained gradual acceleration rather than rapid.

Situation where soot rises rapidly are:
-Going up any level of hill in 6th
-Rapidly accelerating in 5th or 6th.

It seems traveling in higher gears can be quite temperamental. One moment, you might see the soot level go down, the other moment, it may rise rapidly... It might just be a change in speeds of 1-2km/h, a 100 or so in RPM change....

There's probably more, but that's what I can share off the top of my mind now.
 
#22 ·
The Dealership should change your oil for you for free, given it's a known issue.

Anyway, a little update.
My 2015 MT Turbo Diesel Outback has had a new .pak installed on 2 March 2017. It's not a wide release, but a beta one.
What I have noticed so far, is:-
1) active regen abort kicks in a lot earlier than before... so if you sit there idling while the active regen goes on, it will abort after about 100 seconds. This is probably because active regen during idle is not that efficient, but has even got the effect of rising soot levels.
2) The oil dilution goes up a lot slower than it used to... I mean a LOT slower. After a full 12+ minutes of active regeneration, it goes up between 0.1 to 0.2%, as opposed to about 0.6-0.8% it used to.
3) the soot level goes down much slower during active regen.

Between 2 and 3, I am thinking Subaru has may be really calibrated the most efficient post-injection amount and reduced this by a heap, resulting it in sufficient soot burn off, but least oil dilution...

It is yet to resolve any issue with excess soot generation,, however... my car is still going into active regen every 2-3 days, and that is why the problem exist in the first place.
 
#23 ·
Morning all,

Any further update on this and how Subaru are progressing the issue?

Have a 2016 2.0TD Outback with 40k on the clock. Previously a demo car, owned and driver by the dealership owner and serviced at just over 30k by me (was serviced before leaving the dealership also)

I've been told there is a new .pak to be installed and they've charged me for an oil and filter change but I'm guessing that given this is a widely known issue, Subaru should be covering all costs, correct?

Cheers, Ruairi
 
#24 ·
Same problem in my 2011 OB 2.0D

I am having the exact same issue with my OB 2011 model 2.0D (170K km).

No trouble till about 162K km...then all of a sudden, im changing my oil every 1000K (at my expense). To be fair, Subaru are not charging for labour...but the oil aint cheap either!

I have found out from my dealership that I am one of 3 cars (all identical models) that have this issue. The first guy to have the issue is now the guinea pig and to date, they have tested his injectors (all fine) and replaced all his fuel lines to and from the injectors...still no success. Subaru head office has requested the injectors and pump be sent to them for "proper" testing (they don't trust us coastal folk)...but im not holding my breath for any kind of rational explanation from them.

I have ordered my OBD blue tooth plugin and downloaded Torque Pro...see if I can monitor the DPF and its dirty habit of chain regenerations. On the note of software...does anybody think that a software upgrade may have sparked this problem? seems suspicious that a rash (3 cars...all 2011-2013 model) suddenly display the exact same symptoms?

Lastly, if it is the DPF and its stinking regens, im sorely tempted to rip the Flipping thing out and get a remap done to stop the EGR and regens. If anybody has successfully done this, I would be very grateful if you could point me in the right direction...before my engine wears itself down to a nub.

Thanks
 
#25 ·
You are changing your oil because of the "oil dilution" issue?
Have you stated logging your DPF parameters yet? How is the soot level and DPF active regen frequencies going? Mine is highly variable depending on the driving condition and weather. The warmer it is, the more soot it seems to generate, but also the ease of passive regen.



I reckon Subaru should change the DPF active regen programming from my observations... Trigger for finishing up active regen early should also be set at:
1. When the soot level reaches 0%
2. When the DPF estimated temp is above 630degrees C and soot level reached below 20%


From my experience, once these conditions have been satisfied, continued active regen just adds more soot generation... and increases oil dilution to no benefit. Obviously, by (the active regen) injecting fuel between the combustion cycles, it coats the inside of the cylinders with unburnt fuel (the reason the oil dilution happens), which then partially combusts and turns to soot in the next combustion cycle... So the shorter the regen the better.
 
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