DPF Regeneration

andyj

There's no F in Quality..
On the odd occasion I can remember, the exhaust note from my car has changed to become alot louder/sportier.

I've often wondered what this was, thinking it might be a problem.

One day last week, it happened as I got near to home. Once parked on the drive, I got out only to hear the exhaust 'tinking'.

It then occured to me, that this could be something to do with the DPF..... so a quick search on here has found this:

http://www.seatcupra.net/forums/search.php?searchid=7511357

Basically, when the DPF needs regnerating, the ECU increases the fueling, to increase the EGT (exhaust gas temp), which in turn then burns off the carbon build up in the DPF.

Edit: going to keep a note in here, of how often it does it..... can't recall the last time, but it did it today @ 30,700miles

07/06/11 30,700miles
 
Last edited:

Nath.

The Gentlemans Express
Jan 1, 2006
8,620
16
EASTLEIGH, HAMPSHIRE
Correct

As a MK2 Leon DP170 owner I have collected a lot of info on this subject, this is why my soon to be new car is a CR170. so here goes.

There are 2 types of regeneration, passive and active

During long motorway journeys, passive regeneration will occur. This needs no intervention from the engine control unit. Due to the raised exhaust temperatures on a long journey
(temperatures between 350 and 500°C), the procedure occurs slowly and continuously across the catalytic-coated (with platinum) DPF. The catalytic-coated DPF is situated
close to the Engine, therefore the exhaust gas temperature is high enough (500°C) to ignite the soot particles.
Due to this soot is burned-off and is converted into a smaller amount of ash.

Active ‘regeneration’ is when the ECU intervenes when the soot loading in the DPF is calculated to be 45%. The procedure lasts for about 5 – 10 minutes. Specific measures are taken by
the ECU to raise the engine exhaust temperature to above 600°C, these include switching off the exhaust gas recirculation and increasing the fuel injection period to include a small
injection after the main injection. The soot particles are oxidised at this temperature.

The ECU will trigger a regeneration process, if for some reason this is aborted, ie. customer slows down, stops etc, the process will be resumed when
regeneration conditions are once again met, above 60km/h (38mph). This will continue for 15 minutes.
If after 2 attempts of 15 minutes, a successful regeneration has not been possible, the loading will increase. At 50% soot loading, the ECU will continue to
maintain maximum exhaust temperatures of 600°C to 650°C to cause a regeneration process. The system will try to run a regeneration process for 15
minutes. If unsuccessful, the system will repeat this process for a further 15 minutes, if still unsuccessful, the DPF light on the driver display panel will then be lit.



You can monitor the soot level in the DPF with Vag-Com, here's how.

Connect laptop to the car and open Vag-Com
click on select control module
click on 1 engine
click on 8 measuring blocks
block 75 collumn 1 lambda is the soot loading in this case.
You can measure 3 blocks at the same time
block 68 collumn 2 is soot left after regen. A value of 60 means time to replace the DPF

You can also do a forced regen if you do get a blocked DPF, here's how.


Prerequisites (General):

Ignition ON
Engine ON (Idle)
Coolant Temperature above 50 °C (see MVB 002.4)
Particle Filter Load below Specification (see MVB 075.3, VAG-COM should give the specified value)
If the Particle Filter Load is above Specification the Particle Filter needs to be replaced since the car may burn down when regenerating.
Power Consumers ON (Light, Seat Heating, Front/Rear Window Heater, Climate Control)

Conditions (Driving Cycle):

Vehicle Speed between 30-60 km/h (18-37 MPH)
Engine Speed between 1500-2500 RPM (4th or 5th Gear, Automatic Transmission in Tiptronic)
Duration approx. 15-20 Minutes
Exhaust Gas Temperature before Turbo Charger above 700 °C

Drive the car based on the above conditions until the Particle Filter Load is as low as possible (close to 0*%). In case the regeneration fails there can either be problems with the Driving Cycle Conditions or with the Engine Hardware.

[Select]
[01 - Engine]

[Coding-II - 11]

Enable Regeneration by Entering 21295.

[Do It!]

[Meas. Blocks - 08]
Select both Groups at once 070 and 075.
[Go!]
MVB 070.1: Regeneration Status (xxxxxxx1 = Normal Regeneration active, xxxxxx1x = Forced Regeneration active)
MVB 070.3: Regeneration Counter/Timer
MVB 075.1: Exhaust Gas Temperature before Turbo Charger
MVB 075.2: Exhaust Gas Temperature before Particle Filter
MVB 075.3: Particle Filter Load
MVB 075.4: Exhaust Gas Temperature after Particle Filter

Now Start the Driving Cycle and keep watching the Measuring Blocks (2nd Person required).

[Done, Go Back]
[Close Controller, Go Back - 06]



As far as I know the CR170 and CR140 don't have DPF issues because they are a much cleaner burning engine so don't worry too much...................
 
Last edited:

Nath.

The Gentlemans Express
Jan 1, 2006
8,620
16
EASTLEIGH, HAMPSHIRE
I noticed my CR170 doing a regen last night when I parked on the drive. The engine didn't seem to run quite how it normally does, the tick over was a little higher and the exhaust smelled like burning rubber after I had switched off the engine. I took the car out for a short run today and the regen seemed to take about 5-7 mins to complete, it's all back to normal now.

Just thought I would add my experience today to this thread. [B)]
 

OLDOILER

Full Member
Jul 28, 2005
1,292
1
Wiltshire, UK
I noticed my CR170 doing a regen last night when I parked on the drive. The engine didn't seem to run quite how it normally does, the tick over was a little higher and the exhaust smelled like burning rubber after I had switched off the engine. I took the car out for a short run today and the regen seemed to take about 5-7 mins to complete, it's all back to normal now.

Just thought I would add my experience today to this thread. [B)]
Don't hear of many regens on CR's what your driving profile been like over the last few weeks??
 

OLDOILER

Full Member
Jul 28, 2005
1,292
1
Wiltshire, UK
Mine's done about 31k now, and I can recall at least 6 occasions when I've experienced what I beleive to be a regen..... :confused:
No need to be confused !!it's just I must have been lucky so far and mine has not gone into re gen mode yet - must be driving too quickly. ....................................!!!!
 

Nath.

The Gentlemans Express
Jan 1, 2006
8,620
16
EASTLEIGH, HAMPSHIRE
Has anyone seen the DPF light on the dash when it shouldn't be?

As far as I know my Exeo has only ever done 1 regen, the one that I posted about before.
 
Last edited:

Wildie

Active Member
Jun 29, 2011
137
0
ours has done one Active ‘regeneration’ in the 6 mths we had to car wont be using store fuel again it`s not worth the hassle of going through a active regen, not seen a light on yet so must of worked after the 2nd time as the first failed after i had stopped, as for the passive side must be a doing all time at the speeds i go and the last few trips 200miles a time on the motorway.
 

decadent

Active Member
Apr 1, 2012
421
1
Herts
I usually use supermarket fuel and haven't seen the DPF light appear on either of my DPF equiped cars I've had (170 Leon & 170 Exeo).

I do notice the boomy exhaust note though, I've only done 7,500 in the Exeo and have heard it at least 6 times. Didn't notice it in the Leon and did 26,000 miles on that.

Now on 10,700 miles.
 
SEATCUPRA.NET Forum merchandise