DPF questions

[GreyWolf]

In an attempt to crack Enigma 2.0 (without directly talking to the programming Engineers), thought I would share my DPF observations from research & monitoring the VAGDPF app.

It would be great if any others could share their understanding / observations to compare & confirm DPF function.

1. DPF active regen appears to enable via soot mass calculated value 30-32g.
2. Requires min 20km continuous driving to complete cycle. (Open road obviously better)
3. Once the DPF regen is complete: soot calculated 4-5g soot measured 0-1g
4. mg/km value – referenced to the soot mass calculated value.
5. Soot mass measured utilizes sensors: dpf differential pressure, pre-dpf EGT, MAF.
6. Soot mass calculated: EGT & Lambda sensor
7. If soot mass measured is greater than calculated it will override the soot mass calculated (update the value) & enable a regen.
8. When driving if EGT > 350C soot mass measured will maintain value or go down as EGT increases (passive burn) however soot mass calculated continues to increase (+ve mg/km value).
9. Short trips or cold engine driving will increase soot approx. x4.
10. 35g > soot < 40g you get your DPF light. (Go for a scenic drive).
11. 40g > soot < 60g you get your glow plug / MIL. (Hope you have a quality scan tool)
12. > 60g (Damn $$$$)

Other DPF enable pre req's
- 90C Temp
- > 1/4 tank fuel
- > 60km/hr


Hopefully this helps others if having issues.

[Lucas_R]

Hi Lucas_R

Thanks for the update. I think I might trial the app as well. Out of curiosity what is your average mg/km when driving? (negating variation with load/condition). It appears any value > 350C Exh temp is in passive burn state.


It would be great for the other 1500+ views if anyone else can share some data to compare & baseline.

Sorry mate I haven’t looked at the data closely enough to know.

All I really use the app for is to not only keep track of regens, but also to make sure the regens occur after the same/similar distance travelled each time to keep an eye on the general health of the engine (a boost leak or fuelling issue will fill the DPF up much more quickly).

[GreyWolf]

I agree,

It is a great monitoring tool for the price. I use it the same way to record baseline & determine if there are any abnormalities presenting themselves or contributors to increased soot loading.

I imagine as the DPF ages & accumulates ash (from burnt off soot), it will obviously reduce in volume which will increase regen frequency. I suspect this is also factored into the regen calc.

If anyone can share or knows of
- current ash value for your driven km's
- the max ash limit for DPF?

This may help to determine an average suspected life of the DPF.

[GreyWolf]

Something else that may be useful for others.

- Using a phone screen recorder function / app to archive/capture the regen for future comparisons or troubleshooting.

I have noticed variations in the soot mass measured value utilising the phone screen capture function. One prior to the engine being turned off. Then on the very next engine start-up.

Any one else seen this or other abnormalities in monitoring?