P0401 - Cracked DPF?

DubFamily

Veteran Member
Joined
May 30, 2012
Location
Swan Point, MD
TDI
2014 BMW 328D xDrive
Hey all;

There are a lot of threads on this, I know (I am busily searching through them all for some answers and hopefully fixes), some are useful and some are out in left field; but I am trying to narrow it down to the most recent/up-to-date info...

This morning driving in to work my CEL came on steady; a quick scan with Torque Pro while driving gave me a P0401 code. I tried to clear it, shut of and restarted the engine and it was immediately back so no luck on a "ghost" or anything... For reference I have ~136,XXX going in 137K miles on the car, 2012 Golf TDI 6M.

From what I can find so far it appears if P0401 is the only code you have it is almost certainly a cracked DPF?
 

Cabdriver

Well-known member
Joined
Feb 18, 2011
Location
New Jersey
TDI
2009 JSW TDI
P0401 means you have insufficient EGR flow - it doesn't mean you have a cracked DPF, DPF code 18434/P2002/008194 would relate to DPF. There is no particular code to indicate a cracked DPF. DPF codes indicate a is functioning within the correct parameters.

You may simply have a clogged EGR filter, is the MIL on consistently? Having a VAGCOM readout would be helpful to see the values and whether it is an intermittent issue or not. Since you didn't get an EGR valve code - I would venture to say your EGR filter is full or lines are clogged. You could try running it hard for a bit to clear out any blockage - but I advise getting a vagcom autoscan readout and posting the full scan.

Another option is going to the dealer and seeing what they recommend.
 

showdown 42

Veteran Member
Joined
Feb 16, 2012
Location
naples,FL
TDI
2016 TDI touareg
Go to the dealer,claim an emissions problem. Vw should fix based the on going emissions recall. Can't wait to hear what they say.
 

meerschm

Top Post Dawg
Joined
Apr 18, 2009
Location
Fairfax county VA
TDI
2009 Jetta wagon DSG 08/08 205k buyback 1/8/18; replaced with 2017 Golf Wagon 4mo 1.8l CXBB
The P0401, with a sooty tailpipe would indicate a cracked DPF. there are other causes for the P0401, but soot getting past a cracked DPF is one.

this is from a TSB:



you have more miles than would be covered by the 80k emissions warranty on specified devices,

and the DPF is not likely to be included in any fix for the NOX cheat for a car past the 2009 model year.


Looks like you have a VCDS.




you might want to run basic settings 078 (after a drive, you want the temperature to be just a bit over 200 C if you can)

you have to enter the 078, since it is not in the VCDS basic settings pull down menu
 
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DubFamily

Veteran Member
Joined
May 30, 2012
Location
Swan Point, MD
TDI
2014 BMW 328D xDrive
P0401 means you have insufficient EGR flow - it doesn't mean you have a cracked DPF, DPF code 18434/P2002/008194 would relate to DPF. There is no particular code to indicate a cracked DPF. DPF codes indicate a is functioning within the correct parameters.
You may simply have a clogged EGR filter, is the MIL on consistently? Having a VAGCOM readout would be helpful to see the values and whether it is an intermittent issue or not. Since you didn't get an EGR valve code - I would venture to say your EGR filter is full or lines are clogged. You could try running it hard for a bit to clear out any blockage - but I advise getting a vagcom autoscan readout and posting the full scan.
Another option is going to the dealer and seeing what they recommend.
The P0401, with a sooty tailpipe would indicate a cracked DPF. there are other causes for the P0401, but soot getting past a cracked DPF is one.
this is from a TSB:

you have more miles than would be covered by the 80k emissions warranty on specified devices,
and the DPF is not likely to be included in any fix for the NOX cheat for a car past the 2009 model year.
i would be happy scan with a VCDS if you find yourself on he virginia side of the DC beltway in the next few days. (or you can look for someone closer, or a dealer) the VCDS or dealer scan can verify that the blocked flow is in the low pressure or high pressure, and eliminate a few other items.
Thanks for the info guys; what I'd found so far seemed to point to cracked DPF but that's why I wanted to try and confirm :D

meerschm: I have VCDS at home and will scan as soon as I get home to get more detail; this just happened this morning on the way in for the first time but the light is on steady. I actually work in Virginia (Rosslyn) so am away from my VCDS cable currently, unfortunately...


I don't expect VW to cover anything more with my mileage; but to the bolded part above, I don't see how model year would have anything to do with the required fix? A Gen I is a Gen I; MY doesn't change that, no?

Anyway; thanks for the detail; I'll add more info tonight as soon as I can scan it.
 
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meerschm

Top Post Dawg
Joined
Apr 18, 2009
Location
Fairfax county VA
TDI
2009 Jetta wagon DSG 08/08 205k buyback 1/8/18; replaced with 2017 Golf Wagon 4mo 1.8l CXBB
Sent you a PM. I am on your way home if you want to stop by.



for the 2009 model year, the DPF is attached to the NOX cat. later ones benefit from a joint in between.

 
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DubFamily

Veteran Member
Joined
May 30, 2012
Location
Swan Point, MD
TDI
2014 BMW 328D xDrive
So I hooked up with meerschm yesterday and we did some scans quickly... Unfortunately, my home computer downloaded the logs he sent me so I'll have to wait to post them (my parents were on their way through last night so didn't have time to look).

He may be able to post more; but it looks like it's the DPF...

And thanks Mike!
 

meerschm

Top Post Dawg
Joined
Apr 18, 2009
Location
Fairfax county VA
TDI
2009 Jetta wagon DSG 08/08 205k buyback 1/8/18; replaced with 2017 Golf Wagon 4mo 1.8l CXBB
Jason's tailpipe has pretty heavy soot, and some soot on the back end of the car.

1 Fault Found:

001025 - EGR System
P0401 - 001 - Insufficient Flow - Intermittent
Freeze Frame:
Fault Status: 00100001
Fault Priority: 2
Fault Frequency: 2
Reset counter: 255
Mileage: 219924 km
Time Indication: 0
Date: 2042.14.18
Time: 06:36:01

Freeze Frame:
RPM: 1748 /min
Speed: 103.0 km/h
Voltage: 14.36 V
Load: 95.7 %
Load: 100.0 %
Mass Air / Rev.: 430.0 mg/str
Mass Air / Rev.: 450.0 mg/str

With the VCDS hooked up, logged the mileage:

220030 km Vehicle Mileage

His P0401 was just after he started this morning on his drive to work. 100km or so before we looked at the car (the P0401 error did not repeat during that time). by the time we looked the MIL was extinguished.
Ran a couple basic settings.

The BS 078 read, 136 61.2 0 222 (note the 136 is a should be less than 100, and the temp is a little higher than 200C)

The BS 067 shows 426 and 522 a difference of 96, a tad under the 100 noted as should be

These two tell me that the P0401 is likely from the low pressure EGR. Valve seems to work ok, but the pressure over the EGR filter is more than it should be.

BS 003 526 and 350 difference of 176 mg/str, well over the 160 should be. (which indicates the high pressure EGR is ok)

The heavy level of soot, with the error, is a pretty good indication that his DPF is cracked.

( I double posted most of this in the living with a sooty tailpipe thread. hope that is ok. )
http://forums.tdiclub.com/showthread.php?t=445921
 
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meerschm

Top Post Dawg
Joined
Apr 18, 2009
Location
Fairfax county VA
TDI
2009 Jetta wagon DSG 08/08 205k buyback 1/8/18; replaced with 2017 Golf Wagon 4mo 1.8l CXBB
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frugality

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Sep 19, 2003
Location
Spring Lake, Michigan
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none, 2016 GTI
$934 looks to be a good OEM price. My go-to site for OEM stuff at what's usually the cheapest prices is 1stvwparts.com, and they show $984 with a $100 core charge.
 
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