DPF und LMM | Posts 32+

There is no particle sensor there...

You can determine if the DPF is damaged by comparing the differential pressure to the list provided in this forum.

Thank you, Herbert.

Yes, the indicator light came on.
I've already deleted that error message twice, let's see when it reappears.

Today, I took the particle sensor out and it's a bit rusty, but not stuck due to moisture.

The G784 does not require any programming, however, the SSP595 or REP guide states that an adjustment in the control unit may be necessary when replacing the catalytic converter or DPF. I will take a look at that.

Is a refurbished item essentially the same as a new item?

I'll check the relevant settings sometime in the next few days.

Even with the SCR system, an adjustment needs to be made, likely due to the AdBlue injector, even though I haven't replaced it.


Wishing everyone peaceful and reflective holidays.
I will report back later.

J = Model year 2018.
It's likely that the engine is an EA 288, and it might even be a development stage leading to the EA288 Evo. Otherwise, an error message related to the G784 module shouldn't appear.
It's best to check the specific RLF (reference load function) and the build list (in STG01, under "Remarkable Measured Values").
hg
Herbert.

dieselschrauber wrote:

There is no particle sensor there... You can tell if the DPF is damaged by comparing the differential pressure with the list here on the forum.

However, there is.
BOSCH 0281007048 – Particle sensor.
03N906261B

Replaced the defective one with a new one.


I'll go look for the list, thanks.

Hello,

Interesting! The sensor doesn't actually measure "particles" and their size, or whatever. Well, I think the term "particle sensor" is very optimistic and geared towards marketing.

However, it is actually referred to by the manufacturer as a particle sensor G784), and it essentially measures the resistance on a ceramic substrate, which, for example, is reduced by deposited soot.

Details about the function can be found in SSP_564_DE.pdf, page 37.

Since the DPF sensor was hopefully removed for cleaning, the error message is more likely caused by damage during removal/installation, or by connector problems/rodent damage to the connection cables.

If the DPF is actually mechanically damaged, the error message will reappear after a few hundred kilometers, even with a new sensor, if the ceramic surface becomes sufficiently coated with soot again.

Therefore, I would not get my hopes up too soon, but rather rule out any obvious damage to the DPF by performing comparative measurements of the differential pressure.

You should be able to recognize this directly at the exhaust pipe by comparing it to similar vehicles with increased soot levels. If you already see a significant amount of soot, you can save yourself further troubleshooting.

Line 18 in the error log (from the graphic dated December 21st) would be the point of interest for me.
At 0 µA, the control unit likely indicates a sensor problem.
hg
Herbert.

ZTurbo wrote:

According to the parts list, it has the full range of sensor technology installed: And then there's the NOx and particulate sensor: NOx 04L 907 807 AJ Part number 03N 906 261 C.

I already wrote about the particle sensor on the page before .

I've read about how the "particle sensor" works.

And then, even the 0 µA reading was questioned!

Since I don't know the sensor's characteristic curve, the internal resistance could be "infinite" if the sensor is 100% clean (i.e., with no conductive soot particles), and therefore no current would flow. However: Since I have already driven, there are definitely soot particles on the sensor! Therefore, a reading of 0 µA is rather unlikely.

During the journey, the sensor's surface repeatedly heated up to approximately 800°C to remove soot particles, which suggests that the sensor's control unit is apparently functioning correctly.

Could it be that the particle sensor only measures for a certain time *after* the initial warm-up phase, and then only displays the current values? That would explain the 0 µA reading. I'll test this while driving.

The sensor was replaced with a new one after cleaning, as the original one was damaged during removal.
The new, genuine Bosch part was installed according to the instructions, but I will still double-check the connector and wiring.

Yesterday, I ran the engine at idle and recorded various measurements. See the attached file.

What also surprises me is:

Fuel consumption for 180 km = 21 liters.
Time in operating state: 0s (for a measurement of 0 µA? In that case, no current can be measured).
Lambda value before particle filter = 4.5 ?!

Currently, there are no error codes stored in the memory (all have been cleared), and I will be conducting further test drives.

A new error code appeared yesterday: P0673, which indicates a glow plug issue in cylinder 3.
However, this will not affect the P226D.

Hello,

Not all measurable values that are displayed necessarily have to be correctly processed by the control unit, especially when leaving the main road and following a dirt path on the left or right. Anyone who has seen how software development works at many companies understands what I mean.

If I remember correctly, GSK3 is also responsible for measuring combustion pressure, which is used, among other things, as a parameter for controlling the start of fuel injection.

However, it should not have a decisive influence on the soot formation.

Especially with things like yours, it's always questionable which measurement values correspond to which, and whether any of them can even be evaluated.

I suspect that, in addition to checking the wiring, it's more efficient to simply drive the vehicle and then see if everything is okay. You could also take a look inside the exhaust pipe (for soot?), which is a relatively simple process.

Best regards, Rainer.

Quote:

I suspect that, besides checking the wiring, it's more efficient to simply drive and then see if everything is okay. You can take a look inside the exhaust pipe (is there any soot?), and the effort involved is quite manageable.

Herbert.

Hello everyone,

My problem with the DPF persists (see log), and it has now been confirmed by an emissions test at the workshop, with approximately 7 million particulate matter particles.
Please ignore the injector valve for the reducing agent; this was damage caused by a rodent and has been repaired.

I am now looking for a new DPF for the Crafter.

I'm not sure if an original VW DPF is better than an aftermarket one, for example from AHG (the price difference is about 50%).

Are there any practical experiences regarding this? Are there any differences in quality? Are there any problems after installation, after pairing/resetting, etc.?

Recommendations from a specific company?

After my original DPF was so damaged by the company during the (alleged) cleaning process that I now need a new one, I've become cautious.

Could it be that only the coating was damaged by the chemical cleaning agents, and that's why this error (missing substrate) is appearing? Or could it be that damage occurred inside the filter due to the pressure washing?
Sure, I'll translate the text from German to English. Please provide the text you would like me to translate.
Ich denke das der Fehler durch Druckdiff Messung generiert wird? Or?

Thank you in advance for your help and comments!

Hello,

You can easily tell if the DPF is mechanically damaged by looking at the differential pressure of the exhaust gases passing through it. A hole or fracture will result in a noticeably low differential pressure when the engine is running at full throttle.

Comparable values: https://community.dieselschrauber.org/en/viewtopic.php?t=24222

Damage (chemically): Theoretically, yes, you could pour in things like hydrochloric acid or Pattex glue, but no one who's sane would do that.

What about the particle sensor? As long as it has a short circuit to ground, I would fix that first, and above all, compare the differential pressure under load.

If the differential pressure is too low under load, you can remove the DPF (if it's broken). Otherwise, troubleshoot the particulate sensor error and try a DPF regeneration to see if the issue resolves itself.

Best regards, Rainer.

Hello Rainer,
Thank you for the clear statement. I will measure it under full load.

I had just installed the new particulate sensor (it was damaged during the removal of the DPF), so I have no idea why the new sensor is now short-circuiting to ground. Perhaps there's some damage to the wiring from a rodent that I haven't found yet. I'll need to check that as well.

I'll let you know.

Measurement run:

Idle speed: approximately 15 mbar.
Maximum operating pressure: 300 mbar.

300 seems quite high! But it can't be a hole or crack, right?

fowin wrote:

Measurement run: Idle speed: approximately 15 mbar. Maximum operating pressure: 300 mbar. 300 seems quite high!? But it can't be a hole/crack, can it?

Normal values, the DPF is likely not cracked or damaged.

Sure, no problem!

How can I explain the Auger measurement with approximately 7 million particles?