DPF. How to keep it clear with normally local runs?

[Trapper]

Just when I thought it's not happened to me, it did.

Bought my B6 170 SEL in May 2008 and was made redundant Christmas Eve same year. Too old for a new job so for the last 4 years have really only done non motorway local runs, my milage so far is just over 25k.

Started up last week and the orange 'Engine' warning light came on, car ran fine. Took it into dealers who carried out a diagnostic (£35.) and the report was as follows:

"Investigated engine management light on. Carried out guided fault finding. Checked technical found relevant tech information. Requires software update and check pressure sensor, earth point and carry out regeneration."

Cost of above listed at £172.80 inc VAT but warned that there "May be further costs after"

The service guy said that the first warning of the PDF getting blocked is the Orange Engine light, then the Orange circular light - I think he mentioned injectors- the last warning is the DPF warning light. Is this correct?

I took the car for a run up the M1 at a steady 60mph and 2500 RPM covering 40 miles in total, the Engine warning light stayed on and was still on at my return.

I like the car and apart from the DPF I am quite happy to keep it, however having the possibility of a £2k sudden DPF bill is scary!

Once the regen has been completed next week how can I best keep the DPF in good order? Would a run of 40 miles as above once a month be sufficient? I am covering around 4000 miles a year including a couple of 300 mile trips so that means around 3400 or so a year, mostly around town.

Iv'e seen the thread about removing the DPF but am not willing to risk MOT failure later and could end up with an unsellable car.

I could use my savings and buy a Petrol car or Diesel without a DPF but would not get anything like what I have on my SEL and it would still cost me £0000.00's to change so if I can I would prefer to keep the SEL.

[RichardSEL]

B6 170 SEL in May 2008 <snip>the last 4 years have really only done non motorway local runs, my milage so far is just over 25k. Started up last week and the orange 'Engine' warning light came on, car ran fine. Took it into dealers who carried out a diagnostic (£35.) and the report was as follows: "Investigated engine management light on. Carried out guided fault finding. Checked technical found relevant tech information. Requires software update and check pressure sensor, earth point and carry out regeneration."
Cost of above listed at £172.80 inc VAT but warned that there "May be further costs after"
<snip>
I took the car for a run up the M1 at a steady 60mph and 2500 RPM covering 40 miles in total, the Engine warning light stayed on and was still on at my return.

I like the car and apart from the DPF I am quite happy to keep it, however having the possibility of a £2k sudden DPF bill is scary!

Once the regen has been completed next week how can I best keep the DPF in good order? Would a run of 40 miles as above once a month be sufficient? I am covering around 4000 miles a year including a couple of 300 mile trips so that means around 3400 or so a year, mostly around town.

Iv'e seen the thread about removing the DPF but am not willing to risk MOT failure later and could end up with an unsellable car.
<snip>would prefer to keep the SEL.

Not a Derv head here but hopefully this will help you/others: Needs VCDS to do. Also there's been reports of regular use of Millers fuel additive keeping DPF cleaner, and staying away from supermarket fuel. Realise this could be awkward what with being on restricted budget on retirement like me. But found Asda's 1p per litre cheaper than Esso (petrol for me) a false economy as suspect theirs isn't 95 RON coz get better consumption and performance from Esso's

Diesel Particle Filter (DPF) Emergency Regeneration
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The DPF light is a rectangle with dots inside, on the left side of the display. Blinks quickly yellow once when key is inserted.

Contents [hide]
1 1.4l/1.9l/2.0l R4 & 2.5l R5 PD/PPD-TDI
2 2.0l R4 CR-TDI
2.1 Regeneration while Standing/Idle
2.2 Regeneration while Driving
3 3.0l V6 CR-TDI
1.4l/1.9l/2.0l R4 & 2.5l R5 PD/PPD-TDI

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.

Diesel Particle Filter Emergency Regeneration - Ross-Tech Wiki
[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

VAG DISESEL PARTICULATE FILTERS (DPF)
~~~~~~~~~~~~~~~~~~~~~~~~~
(Courtesy of David Bodily Volkswagen Technical Support Specialist)
VW AUDI Forum - VWAF

Detailed below is important information outlining the function and features of the DPF which all members of your team need to be aware of.

DPFs are becoming more commonplace on diesel engines, particularly sizes 2.0L upwards. This is in order to reduce the exhaust emissions as required by european legislation.

The prime reason for a DPF is to reduce particulate matter entering the atmosphere. Particulate matter is found in the form of soot, which is produced during diesel combustion. The DPF traps most of the soot which would normally travel down the exhaust and into the atmosphere. The DPF can hold a certain amount of soot, but not a huge quantity and therefore it needs to go through a process called ‘regeneration’ in order to clear the soot loading. When the soot goes through a ‘regeneration’ process it will be converted to a much smaller amount of ash. The ash is non-removable. There are two 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 action, 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 five to 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, i.e. 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 two 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.

The owners handbook states that the DPF symbol (a yellow square with dots in it) lights up to indicate that the diesel particulate filter has become obstructed with soot due to frequent short trips. When the warning lamp comes on, the driver should drive at a constant speed of at least 60 km/h for about 10 minutes. As a result of the increase in temperature the soot in the filter will be burned off. If the DPF symbol does not go out, the driver should contact an authorised Volkswagen repairer and have the fault rectified. The yellow symbol changes to red.

At 55% soot loading the DPF light is lit on driver display panel. At this point the customer should follow the advice in the handbook. If they ignore this information and continue driving the vehicle until the soot loading reaches 75% without successful regeneration, additional warning lamps will light up. At this point the customer will also be complaining of lack of power, etc.

At 75% regeneration is still possible with the use of the VAS tester. Or by following the above VCDS insturction. Only when the loading is above 95%, is it necessary to replace the DPF unit.

Operating Status System Response

45% DPF Load Level 1 - Normal regeneration

50% DPF Load Level 2 - Regeneration at maximum exhaust temperatures

55% DPF Load DPF lamp and message ("See operating manual") - Regeneration from 60 km/h onwards

75% DPF Load DPF, SYS and MI lamp - Torque limitation, EGR deactivation, Regeneration via VAG or VCDS tester only

95% DPF Load - Replace the DPF Unit

The warranty department has confirmed that if there is no fault on the vehicle and DPF regeneration has been unsuccessful due to the customers driving style and the customers failure to comply with the instructions in the handbook, DPF replacement will not be paid for by warranty.

Common causes for customer complaint:

• Frequent short journeys – Regeneration conditions are not met.
Not recommended for sale in the Channel Islands and inner city driving.

• Customers who continue to drive the vehicle with DPF light on – continued
driving with the DPF light on and without successful regeneration results in
excessive soot loading of the DPF, to a point where it is above 95% loaded.
At this point regeneration is not an option and replacement of the DPF is
necessary.

• Fault 18434 particle filter bank 1 malfunction – common fault code. This does
not only relate to the DPF itself, but the entire exhaust gas handling system. This
can be caused by defective temperature sensors, pressure sensors, additive
system components (if applicable), poor connections, wiring issues, etc.

Important Information

• Before diagnosing a problem vehicle or attempting to perform an emergency
regeneration, it is important to obtain a full diagnostic log and read out relevant
measured value blocks. These MVB’s contain important information on the
condition of the DPF system and are essential in diagnosing the fault. When the
DPF light is illuminated, it does not necessarily mean that the DPF requires
regeneration. For further advice, please contact Technical Support with the
information from the diagnostic log and MVB data.

• If a problem vehicle arrives with the DPF light, the engine management light and
the emissions light on. If during your diagnosis and reading of relevant MVB’s,
you find that the soot loading exceeds 75% (but is still below 95%), an
emergency regeneration procedure must be performed with the VAS/VCDS tester.
Further to this, the customer needs to be educated. They need to understand
why the lights have appeared on the dash panel. Their attention needs to be
brought to the owners handbook instructions, so that they are aware of what the
DPF light means and what to do when it appears. This should prevent
unnecessary repeat visits for regeneration purposes.
I have also found that as the car gets older, some 30K+ miles, you will notice that the regeneration takes place more often.
ALWAYS, check your oil before any long journey, as DPF regeneration can use a fair bit of oil.

Some questions and answers that may help;
Question: The glow plug symbol is flashing. Why? What should be done?

Answer: The DPF regeneration has not been completed during normal driving and now DPF has reached its maximum saturation at which it can still be regenerated. The limit value depends on variant and Model Year, but is in the range of 105% - 125%. Possible causes for this are:
a.) Frequent short distance journeys, i.e. high soot loading while at the same time regeneration of the DPF does not take place because the conditions necessary were not fulfilled.
b.) Frequent interrupted regenerations, i.e. the engine was switched off during regeneration. Applies to short journey drivers who have at least fulfilled the conditions for triggering regeneration. If the glow plug light flashes, the vehicle

i.) Engine running since start for longer than two minutes.
ii.) Calculated saturation higher than 80%.
iii.) Coolant temperature over 70°C for at least two minutes.
iv.) No DPF-relevant faults stored in system.
v.) A defined vehicle speed threshold must have been exceeded (e.g. for greater than 80% loading, 100 km/h)


Question: Under what conditions is regeneration interrupted/ended once it has started?

Answer: Normally when regeneration has been successfully completed, or:
a.) After a maximum regeneration time (20 - 25 min.).
b.) If the engine is switched off or has stalled.
c.) If the engine is left idling for a long time (five - 10 min.).
d.) If 1000°C is detected by the exhaust temperature sensor.
e.) If during regeneration, a fault is detected on the components relevant for combustion (injection/intake system).
If a regeneration is interrupted once started but before it has been 50% completed, the glow plug lamp flashes on the next engine start (cold or hot) and regeneration begins again once the operating conditions (see iii) have been fulfilled.

Question: How long does complete regeneration take? a.) In the most favourable case? b.) In the least favourable case?

Answer: a.) Under constant conditions, i.e. the exhaust temperature necessary for regeneration always lies above the required value, for example during motorway/cross-country driving, the average regeneration time is 10 minutes.

b.) Vehicle conditions such as long down-hill descents, frequent driving in the low-load range (city driving, idling) allow the exhaust temperature to fall. If the conditions for triggering regeneration were fulfilled, the active regeneration time can be extended up to 25 minutes (depending on engine type). If complete regeneration is not possible within this period, the regeneration will be interrupted.

Question: How does regeneration affect the oil life?

Answer: On each regeneration or attempted regeneration, a certain diesel fuel amount is injected into the engine oil which reduces the oil life. If the "INSP" light in the instrument cluster comes on, the engine oil is exhausted and must be changed. Failure to do so could damage the engine.

[Trapper]

What can I say, other than a very large thank you for your reply. I have printed this out and will read later. I went back to the dealers this afternoon and it would appear that I was not actually given the wrong information but the information I was given was confusing hence my thinking that the DPF was soon to depart this earth. I spoke to another member of staff today who - I hope correctly - explained, that my DPF was going to last a long time, around 100k miles if it was looked after. I only needed to take drastic action if I saw the DPF come on intermittently or if it stayed on. Other than that a monthly run on the M1 should keep it in good nick. The Engine light came on due to a problem with the pressure sensors and correcting this would mean the DPF had to be regenerated to keep the EGR and something else correct once the original problem had been corrected.

It made sense at the time!!

Looks like I will be keeping my SEL

Once again many thanks for your informative reply.

Regards
Alan.

[RichardSEL]

Let us know what these pressure sensors are, their part #, and where?

[Trapper]

When I spoke to him the service person said that there was a sensor on the entry point and another on exit point of the DPF, if the Engine Management found a discrepancy in the reading between these sensors that was outside its set parameters this raised an error, hence the warning on my dashboard.
When I had a pair of SU Carbs, a straight through exhaust, all you needed as a drop or two of oil in the carb pots and spanner to check the exhaust hangers- Job Done! Twin Webber 40 carbs were a bit more complicated but nothing like today's systems!
If the repair invoice shows part numbers I will let you know.

Regards
Alan.

[-M-]

You need to make sure the most current engine ecu software is present and that the differential pressure sensor is working correctly as these are common to failure. This is the sensor that reads the difference before and after the DPF.

[Trapper]

Went out in the car this morning, the engine and all other lights went out straight after starting up. I drove for a while and then tried again and again all lights went out. I can only assume that the problem - the PDF - has now regenerated itself and so the sensors are reading within parameter readings.

I have the car booked in for the work to be done on Thursday as per their report:

"Investigated engine management light on. Carried out guided fault finding. Checked technical found relevant tech information. Requires software update and check pressure sensor, earth point and carry out regeneration."
Cost of above listed at £172.80 inc VAT but warned that there "May be further costs after"

I reckon that it may only need a software update? and perhaps that could be done at the next service?

Don't want to spent £172.80 if there is no need too; too old for a job but too young to get my pension!

Regards
Alan.

[Trapper]

Oh well, that was short lived, light came on again yesterday afternoon and stayed on even with a journey up the A1.

[Trapper]

Lights out at last, the invoice shows no parts only the software update and regeneration and recalibration. The cost was less than they quoted at £151.26 so maybe a new sensor was not needed.....

Regards
Alan.

[Trapper]

I Collected the car on Thursday afternoon and drove 8 miles home, the Engine warning light did not come on during journey home. On Friday afternoon I went out and drove around 200 yards and the Engine warning light came and stayed on then and another trip today.

Something does not seem to stack up with this problem.

In my first post I wrote:

The service guy said that the first warning of the PDF getting blocked is the Orange Engine light, then the Orange circular light - I think he mentioned injectors- the last warning is the DPF warning light. Is this correct?

I cannot find any confirmation of this 'series' of PDF warnings.

Why am I not sure? Well, since January 2009 through 2010, 2011 and 2012 my driving style has been fairly similar with maybe 2 long distance runs a year the rest being shopping or excursions, in those FOUR years I have never seen the DPF light come on other than a very rare fleeting glimpse at start up.

Two weeks before the Engine light came on I had traveled up the A1 at a steady 60mph for about 50 miles and later returned with another 60mph for 50 miles, I think that should have been long enough to passively regenerate the PDF. Yes, No??

As said the Engine warning light came on again after only 1 trip of 8 miles following a dealers regeneration, I think there could be another fault somewhere, not connected to the DPF for reasons stated above, I.e. No PDF warning light in last 4 years, similar driving style for last 4 years and a long drive 2 weeks before Engine warning light first showed. The car has not missed a beat all the time the warning light has been on.

I intend to return to the dealer on Monday to find out what they have to say on the subject. I am sure (hope) someone can advise if I am correct or not in my assumptions. Or may be able to shed some light on this. The dealer gave me a sticker for the windscreen stating that if the DPF light came on to drive at over 40mph for 10min. Then below that if I saw the DPF light in conjunction with the Engine and (( )) light to stop safely and call VW service.

Regards
Alan.