Hello! I'm totally green about this but making an effort to get help before I go crazy. Have a Skoda Octavia 1.6 TDI 2012 with problems with DPF regeneration. The DPF pressure sensor has been replaced twice.  Sometimes the regeneration starts and it works several times in a row, but if I turn off the car during the ongoing regeneration, it won't start again. Then I have to run a forced start of the regenring and run and it often jumps into action. When it doesn't work it seems to be running but the only value that goes down is soot mass Measure(g) which goes down very fast but not Soot mass Calc(g) (when it works both go down) 
 

Thanks for any advice and help I can get, but keep in mind that I'm completely new to this. However, I want to try to fix it myself and avoid a workshop.

 

EDIt: As in picture two is when it works, the difference when it doesn't work is that the Soot mass Calc(g) doesn't immediately drop anything, maybe -0.2 very slowly. All other values are roughly the same.

and - the value of mg/km is somewhere between -19 - -40 when it does not work. (when it works it is between -1500 - -3000)

 

Edited 28 October, 20241 yr by ThoKar
added info

My son in law has a caddy van which the DPF would do exactlty as you mentioned. Starts regeneerating then gives up.DPF light on plus a few others It was due to the intercooler leaking. I assume it wasnt getting up to pressure. He replaced the intercooler and did a forced regen. Been ok since then.

Hi Thocar,

 

I have just come back onto the forum to share my knowledge and recent experience.

 

My DPF issue:-    May 2024  dpf light illuminates. Take car on recommended 1500 -2000 rpm 30 minute drive. Dpf light goes out.  1 month later dpf light come on again.  Continue driving to regen the DPF but instead coil symbol light appears as well signifying a possible EGR fault too. Car goes into limp mode.

 

Got car home. Jack up and support car. Drop subframe and remove dpf and flush it out with Wynns. Replaced EGR valve. This is a pig to remove only because of where the bolts are that mount it onto the back of the engine.

 

Reassembled everything. EGR light goes out for 5 mins then returns. DPF remained on. Removed EGR again ( it was an  aftermarket brand ) Put a genuine VW one on. 

EGR light gone and remains off. DPF light still on. Two long drives still not reset and regened. Took dpf off again when diagnostics said soot level still high. ( 35g soot )

Second flush out. Reassembled. Had a quick Garage workshop check of the system who noted erratic injector values. I had replaced a couple of injectors previously

24 months earlier. Seems they were all on the way to failing so replace the full set with a German company reconditioned set. Made an amazing difference to the running of the engine but DPF light still on despite scans showing NO faults.

 

After scratching head raw thinking why not regenerating had a local diagnostics technician with dealer level equipment. the answer was ;-

 

my car was SIX software updates out of date. I had done all the right things which under normal circumstances would have reset the DPF regen cycle. Since VW have had lots of problems with the Siemens injectors there had been several ECU software updates to deal with the problems. My newer injectors had triggered the ECU software to stop the `DPF regeneration cycle on the revised injector values despite them being programmed in with the correct adaptation codes as the ECU software was out of date for the injectors. After weeks of half crippling myself under the car on the drive the problem was electronic.MY dpf had in fact been cleaned out to almost zero soot but would not allow the dpf regen cycle.

 

So question, WHY DOES SKODA NOT INFORM OWNERS OF REQUIRED SOFTWARE UPDATES AS A MATTER OF COURSE?  I saved a couple of  thousand pounds on not getting a new DPF which is what Skoda quite likely would have told me to get. and then update the software.

 

How many owners out have a dpf light that will not go out despite all attempts to clean it and get a regeneration. Consider the software issue. My fix was eventually 

less than £200 to sort out.

Octavia Mk2 facelift 2012 1.6 CAYC.