DPF Regeneration: Polo 1.6 TDI Issues

Hello everyone,

After 10 years of driving a Dacia Duster (with mileage ranging from 0 to 270,000 km) and experiencing absolutely no problems, I've decided to venture back into the VAG group brand and bought an older, used Polo with approximately 165,000 kilometers on it.
It's as if I knew it all along, but at the same time, I bought a diagnostic system here in the shop and have already used it for the first time today.

Polo V 1.6 engine code CAYB.

The following problem:

Today, while driving on the highway, the car suddenly went into emergency mode: The error code (read at home) was...
Freitag,25,August,2023,16:45:23:24731
VCDS Version: RKS 23.3.1 läuft auf Windows 10 x64
http://shop.dieselschrauber.org/en

Adresse 01: Motorelektronik Labeldatei: DRV\03L-906-023-CAY.clb
Steuergerät-Teilenummer: 03L 906 023 D HW: 03L 906 023 D
Bauteil und/oder Version: R4 1.6l TDI H13 9979
Codierung: 00114016002400080000
Betriebsnummer: WSC 00788 648 00255
ASAM Datensatz: EV_ECM16TDI02103L906023D 003014 (VW25)
ROD: EV_ECM16TDI02103L906023AH_003.rod
VCID: 270AFB72BF6B1D826E1-8072
1 Fehler gefunden:

16848 - Dieselpartikelfilter
P2458 00

It might actually be due to my driving style. The Polo has a very long 5-speed gearbox, and during my daily commute (90% highway, the rest city), I've been trying over the past few days to see how low I can get the fuel consumption. The MFA display showed values of around 3.5 L/100 km.
Driving style: Following a truck closely, downshifting on descents, driving with extreme forward awareness, engine RPM below 2000.

Unfortunately, I think I'm now paying the price for it.
What should I do now?

The error cannot be deleted or it reappears immediately.

Regenerative braking is not available as an option when the system is stationary and set to the default setting (04).

Is there only 'forced regeneration during driving' left?

How does one actually do that in practice?
Can I activate this before starting my journey, or do I have to fiddle with it on my laptop while driving?
How do I guarantee a speed of 60 km/h? It seems like it only works when entering the highway and in fourth gear, using the emergency mode?

Thank you and best regards.
David.

Here is where my dangerous half-knowledge comes from:
Okay, I understand. Please provide the German text you want me to translate into English. I will only provide the translation.

Hi,

"The suspected issue is with the particulate filter: 'Differential pressure - DPF sensor reading: 0.00 hPa'. Could a weasel have chewed through the hose connected to the differential pressure sensor?"
I would first check to see if it measures correctly.

Best regards, Rainer.

Hello Rainer,

Thank you for the quick response.
The two hoses appear to be intact at first glance. Everything also seems clean.
I just checked the pressure again while the engine was idling, and it's showing values of approximately 16.xx hPa. When you press the accelerator, the values increase ('go up') (2000 RPM = 32 hPa)...

I can't drive the car today because I have to take care of the children and the house; my wife is 'out' .

If there are no objections, I would like to try performing the forced regeneration while driving tomorrow.
It's quite possible that the engine hasn't exceeded 2000 RPM for the last 1000 km, except during acceleration or gear changes. There is no DPF (Diesel Particulate Filter) light, and I haven't worried about it much, but rather enjoyed the very long gearing and low fuel consumption.

VG
David.

Okay...

First of all, the forced regeneration worked. The emergency mode is gone, and the error memory is clear.

My insights on this (in case anyone has never done something like this before):
1.) You can prepare everything on your laptop first, and then start driving .
2.) When you initiate a 'forced regeneration while driving,' miraculously, the DPF light illuminates on the dashboard.
3.) The journey took forever (over 30 minutes). I was on the highway in 4th gear and trying to keep the exhaust temperature high. The problem is that when going downhill, nothing is being discharged because the exhaust temperature drops down to 200 degrees. In 4th gear, my Polo reaches 180 km/h according to the speedometer. However, you don't have to drive at full throttle all the time; flat stretches are best. 'Going uphill' usually means 'going downhill' afterwards, which unnecessarily extends the walk.
4.) When the soot mass was below 5 grams (I don't know the exact value), both the DPF and glow plug warning lights went out.
5.) After clearing the error memory, the EDC light also turned off.

Not clear to me:
1.) Why had I never seen this stupid DPF light before? It would be great if it lit up so that drivers know they need to drive in a way that allows the DPF to regenerate.
'Could it be that my extremely aggressive driving style prevented the DPF from regenerating properly? (I'll keep an eye on this now; I know that the limp mode kicks in when the soot mass reaches 24 grams).'
3.) Oil analysis results: 1.7xxxxxg. What is this strange value? The car has 165,000 km on the odometer; shouldn't there be more in it?

@docsnydor:

"I'm sorry, the deletion was an unintended side effect of profile changes. There was a bug in the relevant module that we hope has now been fixed. Please simply re-register."

Quote:

1.) Why had I never seen this stupid DPF light before? It would be great if it lit up so that the driver knows they need to drive in a way that is suitable for the DPF to regenerate. "Could it be that my extremely aggressive driving style prevented the DPF from regenerating properly? (I'll keep an eye on this now; I know that the limp mode kicks in when the soot mass reaches 24 grams)." 3.) Oil ash content read: 1.7xxxxxg What is this strange value? The car has 165,000 km on it; shouldn't there be more in there?

1.) Depending on the ECU software, the same issue occurred with my wife's car and was only resolved after an update.
2.) Possible. Possibly too much short-distance travel and not enough heavy loads.
3.) Resetting the ash mass/ash volume reading in the diagnostic system, with or without (a pointless action) removing ash from the filter.

I'm back again .

I'll keep an eye on it.
It was probably underloaded. I drive 60 km twice a day, which should be more than enough.

I haven't had the car for very long, so I haven't had a chance to gain much experience with it yet. Perhaps this is a good opportunity for me to get back into using VCDS. It's been a while since I last used it; back then, it was still VAG-COM in version 1, with a Chinese interface. The 1Z in the 35i was my last TDI, which I sold in 2006.

Welcome! It might also be a good idea to occasionally check the coolant temperature in the engine control unit to ensure that operating temperature is reached. Otherwise, regeneration may not occur.