Morning,

              Can some-one answer in detail how the DPF works/is-supposed to work ?

 

Queries Below:

 

 

 

• What Triggers a Re-Gen
• What Triggers the DPF light
• What Triggers the Coil Light
• What Triggers the EML
• What tells the ECU the Re-Gen is completed satisfactorily and extingueshes the DPF light

 

• What are the thresholds for % and g in measuring block 068
• How many sensors are there in the system controlling it

 

 

Thanks in advance

 

Andy

Hi Andy,

 

I found myself also wanting to know this type of info. Some basic info is in the attached text document attached and more info can be found in the VW self study pdf at http://www.volkspage.net/technik/ssp/ssp/SSP_336.pdf. Did try to attach this pdf but the file was too big.

 

Hope this is of help.

 

Tim

 

 

 

 

 

DPF_regen_info.txt

All of your questions depend on the load on the DPF i.e. how much soot has been caught in it.

 

The level of soot and the abilty of the DPF to clean itself directly relates to which lights you see and when.

 

Click on the image to make it bigger...

 

So what is the load in grams Vs the % figure that you see through measuring block 068 ?

% is soot, g is ash.

Sent from my Nexus 4 using Tapatalk

Yes, so which one triggers the DPF light ? I was of the impression it was the % figure but the above graph suggests the g value ?

Soot content, helpfully the graph gives soot in g.

Sent from my Nexus 4 using Tapatalk

page 56 on has eveything you need to know about DPFs and regens

 

http://www.natef.org/NATEF/media/NATEFMedia/VW%20Files/2-0-TDI-SSP.pdf

so what % level should a re-gen be requested ? And how long should it take (very roughly) for the next one to be required ?

VCDS gives specification as 40% soot, 60g Ash - I was led to believe at 40% a re-gen is requested, after 4 failed re-gens the DPF light illuminates and if after the re-gen run it doesn't clear you get the DPF light, EML Light and flashing coil light along with limp mode ?

 

My light comes on at 18% soot with the Ash at about 1g (post cleaning). Post DPF re-gen run it can be back on after a week.

My light comes on at 18% soot with the Ash at about 1g (post cleaning). Post DPF re-gen run it can be back on after a week.

 

That doesn't sound right. I can only assume that VCDS calculates the soot and ash content via monitoring the gas flow, pressure and temperatures between the two ends of the DPF?

 

These readings are therefore heavily dependant on the sensors working correctly.

 

We all know that if a sensor fails it brings on the EML but we also know that in the time running up to a failure the sensor can work incorrectly without warning.

 

If you are getting the light at 18% then something sounds iffy to me.

The funny thing is there is no fault codes when the lights come on, the G450 had 1 pipe snapped off so was confident that would sort it but after a week ther DPF light was on again with the % at 18 ! Did the usual 4th at 2000 rpm and out it went. Whilst i do relativley short journeys im going 40 - 50 most of the time and do long trips at weekends so I'd expect the re-gen time to be more than 1 week !! Also the DPH has only done 20 odd K and has been cleaned.