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Discussion Starter · #1 ·
Yeah, great way to end the day. SO I had the exhaust pressure sensor replaced today (p2456 error). Drive to work and back (about 80Km each way) and no issues. Wife and I go out and I get the DPF symbol, then a Engine warning message then a flashing GP.

I go home, check the codes and everything looks related to the DPF. I clear the codes, go for a drive, not too hard, but no errors.

So, I can't figure out how to check the DPF levels, and what would be good or bad. The RossTech forms seem to be for the 2.0L TDI, not the 3L CATA. So Channel 75 doesn't show DPF Levels.

Where do I check the soot level, and what are me options (I know about a DPF delete :))
 

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My understanding is ash is soot that's been burned & collected in the DPF. That number increases over time until it reaches the prescribed upper limit. Your ash load is 0.30ml. Close to zero. The upper ash limit for a 2.0L TDI is apparently 175ml. I can't find what the limit is for the 3.0L.

Not sure how to interpret those other numbers. It may have something to do with exhaust gas pressure in front of, and behind, the DPF. The higher the difference, the more soot has been collected and will be converted to ash by regeneration. So the delta should be lowest immediately following a regen.

Someone correct me if I'm wrong.
 

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If this is showing DPF numbers, is this good or bad?

The Australian V10 cannot do a forced regeneration on the DPF as we have the Eloy's fluid system but with the US version having the fuel based DPF injection system will it do a forced regen ?
I doubt it but a question?


Otherwise remove them have them cleaned reset the soot measurements and go again.


regards
Drag
 

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So, I can't figure out how to check the DPF levels, and what would be good or bad. The RossTech forms seem to be for the 2.0L TDI, not the 3L CATA. So Channel 75 doesn't show DPF Levels.
I once had my DPF soot load checked during service, and the limit for the CASA engine is 460 ml. I'm not sure if the same applies to the CATA engine. I think it at least can't be too far from that figure...

I, too, have possible soot problems, but probably both the symptoms and cause are different:
http://www.clubtouareg.com/forums/f93/engine-light-lit-glow-plug-light-blinking-and-limp-mode-244969.html
 

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The Australian V10 cannot do a forced regeneration on the DPF as we have the Eloy's fluid system but with the US version having the fuel based DPF injection system will it do a forced regen ?
I doubt it but a question?


Otherwise remove them have them cleaned reset the soot measurements and go again.


regards
Drag
Drag, the OP has the 3.0l not the V10.

MJHandy, have you seen this tread?

http://www.clubtouareg.com/forums/f80/dpf-state-of-health-227265.html

TonyB
 

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Discussion Starter · #13 ·
So a quick update. When the sensor was replaced the DPF was checked and was fine (185,000 km). The 'ghost codes' are being checked and hoses being checked for a blockage.

So far better news than hearing I needed a new DPF.

I cleared all the codes yesterday and didn't save them. My bad.
 

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Found this document that gives some expanation on the DPF I saved some time ago, apologies for not acknowledging the originator but I didn't keep a record of it's origin.

TonyB

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")

75% DPF Load DPF, SYS and MI lamp Torque limitation, EGR deactivation,

Regeneration via VAG tester only 95% DPF Load Replace the DPF Unit
 

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Discussion Starter · #16 ·
Turns out the TSB for the sensor wasn't done correctly. The dealer was kind enough not to charge me for the work. I said thanks, i'm glad i'm not paying for something you idiots didn't do correct the first time.
 

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Turns out the TSB for the sensor wasn't done correctly. The dealer was kind enough not to charge me for the work. I said thanks, i'm glad i'm not paying for something you idiots didn't do correct the first time.
They did mine correctly (according to the invoice) and my differential pressure sensor still failed...probably should have pressed them on that. Took about 2 years/20k mi to fail after the TSB was implemented.
 

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Discussion Starter · #18 ·
They did mine correctly (according to the invoice) and my differential pressure sensor still failed...probably should have pressed them on that. Took about 2 years/20k mi to fail after the TSB was implemented.

i brought a full scan in and the TSB to prove they hadn't done it right. Still, it was nice of them to not charge for the second attempt. :)

So far so good, no CEL's, next is the emission test.
 

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Emission test at the 7th year, I guess my test is just around the corner too. Seven years goes by fast. Hope your test goes well.
 
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