DPF emergency regen when loading is over 45 grams

Hello everyone.

I have a car (2.0 TDI, code CBBB) which has got the DPF and CEL lights on plus Glow Plug light blinking.
The reason for that is clogged DPF. No other fault codes present.
I used VCDS to check and it seems that the loading is just over the 45 g maximum - it's at 46 grams.

I am aware that 45 grams is the absolute maximum, however, I recall someone here in the forums performing an Emergency Service regen with values higher than 45 g.

Could someone point me into the right direction to try to regen it on my own risk? Yes, I do have a couple of large fire extinguishers - one in the cabin, another one in the trunk

Thanks

you may have a slightly different system

but here is the idea.

there are two soot estimates.

measured

and calculated.

(both are really models which indirectly estimate the actual soot values.)

the calculated soot value keeps track of how the car is driven.

the measured soot value includes pressure and flow measurements in the mix.

the calculated just keeps going up until a regen, the measured goes up and down as passive regeneration does its thing.

if the calculated is too high, but the measured is less, you have a chance.

you can use VCDS (or other tool) to trick the computer. tell it you replaced the DPF, and it will reset the caclulated soot value to 0.

the measured soot value should cause a regen, and you are good to go.

if the measured soot value is too high, (and not due to a bad sensor elsewhere). better plan to clean the DPF.

there is a couple different ways to make this happen.

with the scan tool and do a reset with saying that you installed a new DPF and going that way

or you can drive in 2 or 3 gear for with keeping the rpms above 2500 or something close for a minute or something like that.....i cant remember the exact details but there is a method like this that will usually work

dig a little in some of the old threads and you will find the exact way with RPS and Time it takes to make it regen

Unfortunately both, the measdured and calculated values are over 45
Will try to play with VCDS and see if I can get something.

All the sensors (pressure and temperature) are OK. They seem to be reporting correct values.
Will update once I have some information.

Thanks guys!

http://forums.ross-tech.com/showthread.php?4676-DPF-Force-regeneration&p=47436&viewfull=1#post47436

it has been said that oven cleaner can be used to clean out the DPF.

hm... Interesting. Probably I will need to put some oven cleaner through the G450 sensor tube and then pour some water through a funnel to rinse it.
The goal is to get it slightly below 45 g so that it will be able to regen itself.

pay close attention to the warning labels on any oven cleaner you think about using. that stuff is not good for you. eye, skin and breathing protection are advised.

I ended up purchasing the special DPF cleaning foam. Removed the tenmperature sensor before the DPF and sprayed entire can. Followed the instructions - let it sit for 20 minutes then took it for a drive.

After driving measured soot dropped down to about 4 grams while calculcated increased to 47 or so.
Forced regen was not starting so I tricked the computer as the DPF would have been replaced. Car still in limp mode.

But now I got an underboost code (pressure control range not reached).
I realized that the turbocharger doesn't build any boost at all (it's maxing out at ~1150 mbar) in any situations (hard acceleration, stready cruise, etc).

So looks like the clogged DPF is just a cosequence of failed boost control.

Any hints on where to start looking? I've inspected the intercooler plumbing and there are no visible boost leaks...