Subaru Forester DPF Light

[Bluemikey]

HI all

Can anyone on here help or give me a pointer in the right direction, DPF Light came on back in October 2020 (cracked rubber intake hose) Car was fixed and cleared with DPF Clean, Fast forward to 8 weeks ago and light came back on flashing, took to garage for clean they told me the turbo duct pipe was broken so i ordered a new pipe (£248) fitted pipe took car up motorway on a regen but nothing! Car was running fine, just had it in local garage and they have had it for 3 days they have taken off the DPF and cleaned it thoroughly done a regen but light wont go off they managed a forced regen yesterday it came down to 136% but would not go any lower, this morning they took it again to try a forced regen on the road but again light staying on they have reset the oil dillution and still nothing also put on a new DPF sensor. I am baffled now and am determined not to go to subaru. Any help would be appreciated

[stuartie]

Hi get them to check the ash content with the diagnostic machine, they should be able to access the parameters which should tell them the fill level of ash and what the threshold for the ash should be, unfortunately if the ash content is too high you will have to either remove the dpf and get it put in an autoclave oven to get the ash out or a company such as terraclean with a big fancy machine should be able to clean it out, the problem is the soot gets burned off during a regeneration which creates the ash which can't be burned off as its ash, a lot of these dpf cleaning fluids are not up to the job they might remove some of the soot and carbon build up but not ash also it will not regen if there is an active fault, do you know what fault is coming up on their diagnostics 

[Bluemikey]

HI stuartie

               Yes the fault code was/ is P2463 and P246C

[stuartie]

The first fault code is for soot fill level and the second for reduced engine power because of the soot level, the dpf won't regen if there are active faults and because the soot level is 136% it won't regen even if you were to manage to get the fault codes deleted, you will have to tell the ecu that a new dpf has been fitted which should set all the parameters back to 0% then try do a forced regen again then if it works you'll have to change the oil and filter 

[Bluemikey]

HI stuartie

            Many thanks for that answer any idea how i get the ECU to recognise it being a new DPF? Also the garage assures me the DPF is clear of soot but just showing the reading of 136% i have just took it up motorway @ 70mph in 4th for 20 mins but no joy i did reset the oil dillution before i started but again no joy.

 

 

[stuartie]

The garage you are using will have to use their diagnostics to tell the car they have fitted a new dpf, I would also have them check the egr valve incase it has jammed shut/open as this can also cause dpf faults and get them to check the differential pressure sensor, this sensor measures the back pressure before and after the dpf honeycomb and this is how the ecu calculates the fill level if one of these pipes is blocked with carbon it could give a false reading, the only way to really know how much soot there is inside the dpf is to trust what the diagnostics are telling you or taking it off and shining a light through, 

[Bluemikey]

Brill thanks for the info Stuartie i will get onto it,