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 REPleit manual 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 refurbishment like getting a new part?

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

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


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

J = Model year 2018.
It's likely an EA 288 engine, and it may be a development stage leading towards the EA288 Evo. Otherwise, an error message related to G784 should not appear.
The best approach is to use the specific RLF (resource list file) and the bill of materials (as mentioned in STG01, note). Check the measurements.
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 in the forum.

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

Defective item exchanged for a new one.


I'll go look for the list, thanks.

Hello,

Interesting! The sensor doesn't actually measure "particles" or their size, per se; well, I find the term "particle sensor" to be quite optimistic and geared towards marketing.

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 cleaning sensor was hopefully removed, 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 verschandeln ceramic surface becomes sufficiently blackened 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 identify these features directly at the exhaust pipe, especially when comparing them to similar vehicles with increased blackening. If you can already see a significant amount of black soot, you can stop troubleshooting further.

Line 18 in the error log (from the graphic dated December 21st) would be the point of interest for me.
The STG (Steuergerät) likely indicates a sensor problem when the current reading is 0 µA.
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, 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 burn-in phase, and then the values for current are measured and displayed? This would explain the 0 µA reading. I'll test it out 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 the 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 measurement = 0 µA?? In this case, no current can be measured).
Lambda value before particle filter = 4.5!?

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

A new error code appeared yesterday: P0673 Glow plug circuit malfunction, cylinder 3.
But this will not affect the P226D.

Hello,

Not all measurable values that are displayed necessarily have to be correctly provided 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 things operate in software development 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 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 and then see if everything is okay. You could take a look inside the exhaust pipe (to see if there's any soot?), it's not a very complicated 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 (maybe there's soot?), but 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 fuel injector 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 best practices? Are there any differences in quality? 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 chemical cleaning agents, and that's why this error (missing substrate) is appearing? 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.
I think the error is being generated by the pressure differential measurement. 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. Hole/break = noticeable low differential pressure at full throttle.

Comparison values: /viewtopic.php?t=24222

Damage (chemically): Theoretically, yes, you could pour in hydrofluoric acid or Pattex glue, but no one who knows what they're doing would do that.

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

If the differential pressure is too low under load, you can remove the DPF (which will be damaged). If not, troubleshoot the particle sensor error and check (try a DPF regeneration) to see if everything 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 (as the old one 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 will also check that.

I'll let you know.

Measurement run:

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

300 seems quite high, doesn't it? But it can't be a hole or a crack, either.

fowin wrote:

Measurement run: Idle speed: approximately 15 mbar. Maximum operating pressure: 300 mbar. 300 seems quite high, doesn't it? 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 (AU) measurement with approximately 7 million particles?