AUDI KLUB

VAG DISESEL PARTICULATE FILTERS

Courtesy of David Bodily Volkswagen Technical Support Specialist

Diesel Particulate Filter (DPF^*)

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

Diesel particulate filters 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 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.

The owners handbook states, the DPF^* symbol 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.

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. 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
Regeneration from 60 km/h
onwards
("See operating manual"Wink
75% DPF^* Load DPF^*, SYS and MI lamp
Torque limitation, EGR^*
deactivation,
Regeneration via VAG 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 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 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.

David Bodily

Volkswagen Technical Support Specialist





Here is details from Ross-Tech support page about a mobile forced regeneration:

1.4l/1.9l/2.0l R4 & 2.5l R5 PD/PPD-TDI^*

Diesel Particle Filter Emergency Regeneration
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]


2.0l R4 CR-TDI^*

With the newer CR-TDI^* engines there are 2 different types of regenerations available depending on the actual soot mass/load. If either the calculated or measured soot mass is above 30g but below 40g you can initiate a regeneration while standing (Idle will be raised ETC^*.), a forced regeneration while driving is also possible. Once the values are above 40g (but below the max 45g) the regeneration while standing is no longer available and the regeneration while driving is the only way.
Regeneration while Standing/Idle

Prerequisites (General):

Ignition ON
Engine ON (Idle)
Fuel Tank at least 1/4 full
Transmission in Neutral/Park
Parking Brake engaged
Coolant Temperature above 70 °C (see MVB 002.4)
Particle Filter Load below Specification (see MVB 108.2/3, VCDS should give the specified values)
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)
Engine Hood Closed

[Select]
[01 - Engine]

[Security Access - 16]

Enter the Code shown by VCDS next to Adaptation Enabling (e.g. Regeneration while Standing)

[Do It!]

[Basic Settings - 04]

Select Block for Regeneration while Standing

[Go!]

Follow the Instructions on the Screen

[Done, Go Back]

[Meas. Blocks - 08]
Select Blocks 099 and 108 at once.
[Go!]

MVB 099.2: Exhaust Gas Temperature before Turbo^* Charger
MVB 099.3: Exhaust Gas Temperature before Particle Filter
MVB 099.4: Exhaust Gas Temperature after Particle Filter

MVB 108.2: Particle Filter Soot Mass (calculated) Alternate group 241.2 if 108 is blank
MVB 108.3: Particle Filter Soot Mass (measured) Alternate group 241.3 if 108 is blank

Now let the Car run with Raised Idle until the Particle Filter Load is as low as possible (close to 0 %).

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

Regeneration while Driving

Prerequisites (General):

Ignition ON
Engine ON (Idle)
Coolant Temperature above 70 °C (see MVB 002.4)
Particle Filter Load below Specification (see MVB 108.2/3, VCDS should give the specified values)
If the Particle Filter Load is above Specification the Particle Filter needs to be replaced since the car may burn down when regenerating.
If the Particle Filter Load value in MVB 108 is blank, use alternate group 241.2/3 instead.
Power Consumers ON (Light, Seat Heating, Front/Rear Window Heater, Climate Control)
Engine Hood Closed

Conditions (Driving Cycle):

Vehicle Speed above 60 km/h (40 MPH)
Engine Speed between 2000-2500 RPM (4th or 5th Gear, Automatic Transmission in Tiptronic^*)
Duration approx. 10-15 Minutes
Exhaust Gas Temperature before Turbo^* Charger above 170 °C (MVB 099.2)
Exhaust Gas Temperature before Diesel Particle Filter above 150 °C (MVB 099.3)
Exhaust Gas Temperature after Diesel Particle Filter above 150 °C (MVB 099.4)

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]

[Security Access - 16]

Enter the Code shown by VCDS next to Adaptation Enabling (e.g. Regeneration while Driving)

[Do It!]

[Adaptation - 10]

Select Channel for Regeneration while Driving

[Read]

Enter/Save 1 as new Value.

[Save]
[Done, Go Back]

[Meas. Blocks - 08]
Select Blocks 099 and 108 at once.
[Go!]

MVB 099.2: Exhaust Gas Temperature before Turbo^* Charger
MVB 099.3: Exhaust Gas Temperature before Particle Filter
MVB 099.4: Exhaust Gas Temperature after Particle Filter

MVB 108.2: Particle Filter Soot Mass (calculated)
MVB 108.3: Particle Filter Soot Mass (measured)

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

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


3.0l V6 CR-TDI^*

Prerequisites:

Ignition ON
Engine ON (Idle)
Oil Temperature above 70 °C (see MVB 007.2)
Particle Filter Load below 68g (see MVB 104.3)
If the Particle Filter Load is above 68g the Particle Filter needs to be replaced since the car may burn down when regenerating.
Engine Hood CLOSED
Parking Brake ENGAGED
Transmission in (P)ARK
Temperatures at the Exhaust System may rise up to 300 °C!!!
No Fault Codes Stored
Power Consumers ON (Light, Seat Heating, Front/Rear Window Heater, Climate Control)

The Regeneration may take up to 40 minutes, the engine speed automatically increases to about 1500 RPM.

[Select]
[01 - Engine]

[Coding-II - 11]

Start Regeneration by Entering 10016.

[Do It!]

[Meas. Blocks - 08]
Select all 3 Groups at once 100, 101 and 102
[Go!]
MVB 100.1: Engine Speed
MVB 100.3: Regeneration Counter/Timer
MVB 100.4: Regeneration Abort recognized (0 = No Abort/1 = Abort recognized)
MVB 101.4: Regeneration Status (001 = Heating Up, 010 = Regeneration, 100 = Cooling Down)
MVB 102.1: Temperature before Catalyst
MVB 102.2: Temperature before Particle Filter
[Done, Go Back]
[Close Controller, Go Back - 06]