P226D00 - Particulate Filter Deteriorated/Missing Substrate Bank 1

[Caravelle Dan]

Good evening, it might not be related but since having some work recently (gearbox out) I am getting this fault. It is very intermittent and sometimes doesn't occur for a while but other times it will being on the EML.

I have checked the pipework to the differential pressure sensor and that seems ok.

I disconnected at the Cat and applied a little pressure to see the sensor reading change and there didn't appear to be any leaks.

However what I have noticed is that when I'm driving the 'Particle Filter, diff pressure Sensor 1 bank 1' (which I assume is the pre DPF sensor) reads approx 20-100mbar but when I'm at idle this drops to around 1mbar which is less than Sensor 2 (I assume post DPF). Surely the pressure can not be less before the DPF than after?
Maybe I am missing something?

This is at idle:


And driving:

 

[mmi]

All those are sensor 1 raw data - for some reason there are two raw values available for the sensor. I believe the value 1 is the "real" one.

I think OBDeleven "Particle filter, air pressure sensor 1 bank 1, raw value" would be better one for the monitoring (actuially it's the same as "raw value 1" above but has better resolution).

Have you seen these posts about P226D

[T6_measured] Monitoring DPF regeneration, DPF condition, EGR operation

@ebiii Attached an addendum to Torque - containing the following T6 PIDs "T6-01 Lambda" "T6-01 NOx sensor" "T6-01 Particle sensor current" "T6-01 Particle sensor operation time" NOTE: "T6-01 Particle sensor operation time" will be logged only once in 10 seconds - to not unnecessarily slow down...

www.t6forum.com

 

[Caravelle Dan]

@mmi OK thanks I'll have a look and read the attached.

Do you know if there is anyway with OBDeleven to see exactly what occurred that caused the fault? It would be interesting to know the engine state at the time it went into fault to try and see whats occurring.

I'm leaving towards the DPF having an internal crack as I also sometimes get NOx Efficiency errors and my tail pipe has some soot.

Just want to try and rule all other possibilities out as a DPF isn't cheap!

 

[mmi]

Do you know if there is anyway with OBDeleven to see exactly what occurred that caused the fault? It would be interesting to know the engine state at the time it went into fault to try and see whats occurring.

I'm afraid that for this fault the data is about when the "soot leak" test was performed. As shown in the other thread the ECU just periodically runs a test for soot.
By the fault code there should be so called freeze frame - captured when fault was detected. Unfortunately in OBDeleven it's decrypted - under "Unknown ambient data"

I also sometimes get NOx Efficiency errors and my tail pipe has some soot.

I believe the NOx efficiency is not related at first - eventually could be when NOx catalyst also gets sooty. The soot in tail pipe is a definite sign of a broken DPF.

Also no pressure loss at idle is not a good sign - mine shows 5-10 mbar (depending on exhaust temperature)

 

[Caravelle Dan]

I'm afraid that for this fault the data is about when the "soot leak" test was performed. As shown in the other thread the ECU just periodically runs a test for soot.
By the fault code there should be so called freeze frame - captured when fault was detected. Unfortunately in OBDeleven it's decrypted - under "Unknown ambient data"

Ah ok, that makes sense, I saw the 'Ambient Data' shame we can't analyse this with OBDeleven. I assume VCDS would give more detail?

I believe the NOx efficiency is not related at first - eventually could be when NOx catalyst also gets sooty. The soot in tail pipe is a definite sign of a broken DPF.

Also no pressure loss at idle is not a good sign - mine shows 5-10 mbar (depending on exhaust temperature)

This all confirms what I thought, I knew about this issue when I bought it and had some money off the price off incase it required a new DPF. I just wanted to make sure before diving in! All indications are a cracked/perforated substrate I guess. Not great for only 74k miles!

I did a couple more measurements today, I am assuming the 'Adapted Value' is the actual differential pressure and my readings are well below what you suggest.

This is at warm idle:


This is stationary at 2500RPM:


I appreciate the feedback! Thanks.

 

[mmi]

I assume VCDS would give more detail?

Yes, below a VCDS snippet (freeze frame, or presumably OBDeleven "unknown ambient data") @nazarko1984 posted in thread Engine codes and DPF.

32110 - Diesel Particulate Filter (Bank 1)
          P226D 00 [039] - Damaged or Subrate Missing
          Not Confirmed - Tested Since Memory Clear
             Freeze Frame
                    Fault Status: 00000001
                    Fault Priority: 2
                    Fault Frequency: 1
                    Mileage: 138578 km
                    Date: 2023.03.17
                    Time: 17:48:03

                    Engine RPM: 828.75 /min
                    Normed load value: 30.6 %
                    Vehicle speed: 0 km/h
                    Coolant temperature: 89 °C
                    Intake air temperature: 21 °C
                    Ambient air pressure: 1000 mbar
                    Voltage terminal 30: 13.140 V
                    Unlearning counter according OBD: 40
                    Particle sensor: time in op. mode measurement: 0.0 s
                    Particle sensor: measuring current calculated: 0.0 µA
                    Particle sensor: cleaning deviation reaction time: 1.000
                    Particle sensor: exhaust temperature: 14.7 °C
                    Particulate sensor: status condition automation: 4
                    Particulate sensor: status condition automation: Regeneration following soot particles plausibility check

I am assuming the 'Adapted Value' is the actual differential pressure

Agreed. It's kind of "calibrated" value - actually follows very closely (typically < 2mbar) the "Particle filter, air pressure sensor 1 bank 1, raw value".

 

[Caravelle Dan]

@mmi, ok thanks for the feedback, you've confirmed what I thought which is my DPF is knackered haha.

I think I have sourced a genuine new unit, I dont suppose you know if OBDeleven is capable of doing the adaption for the new DPF and if so what specific adaptions are required? Or is this a VCDS only job?

 

[mmi]

OBDeleven can do the adaption -
Control Units > Engine > Adaptation > Adaptation of ash mass > 0 grams

 

[Caravelle Dan]

OBDeleven can do the adaption -
Control Units > Engine > Adaptation > Adaptation of ash mass > 0 grams

Ah as simple as that, I thought there would be several things I would need to reset! Thanks.