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Oil ash residue

Posted: Wed Apr 08, 2020 5:36 pm
by Imi 2 imi
Hi all
So I have recently brought a skoda octavia and have issues with the dpf light coming on after a few hundred miles which results in taking the car on a burn to make the light go off.
So I have invested in a carista obd reader and got the vag dpf app.

Could someone tell me if my dpf looks healthy or not (dpf light came on yesterday so took it on a drive and light went off)

Nothing is showing in the oil ash residue- 0.0 is this normal or not?

Re: Oil ash residue

Posted: Thu Apr 09, 2020 11:30 am
by admin
The parameter is correctly read, this means it exists in the ECU parameter list.
The reasons why it's at 0.00 can be:
  • your mileage is very low and the oil ash deposit is also very low so until it will increase a little, you'll see 0
  • this parameter is "fake" in the ECU, this means that the ECU never update the value despite it's present; in this case you could check all other engine groups in VAG DPF looking for some that let you read the oil ash

Re: Oil ash residue

Posted: Tue Apr 14, 2020 5:48 pm
by Imi 2 imi
Hi
I had a carbon clean person come out to check the dpf to see if it was blocked or not as the car is on 110k the person mentioned the dpf isnt blocked.
He did however hook up his obd reader and said he reset the dpf values so this could be why its 0.

The vag dpf app is great to monitor etc however what is the best way to keep on top of the dpf in terms of not letting it get to a stage where the light comes on?

Is there a tool/app out there do do a regen so I wont have to wait till it gets to 100% on the vag dpf app to do a regen?

Thanks

Re: Oil ash residue

Posted: Tue Apr 14, 2020 5:56 pm
by Imi 2 imi
From the last regen it was around 150 miles until the light came on so does seem like it's coming on quick.
The carbon clean person mentioned it could be the dpf pressure sensor but I'm not sure.

When the dpf light comes on and if I dont take it for a long burn and continue to drive in short trips the I have a engine management light on and a flashing coil light.

Then I have to pay a trip to a local garage to do a reset on their snap on machine.

The car is used as a taxi so more city driving rather than long distance.

Any suggestions or advice on this issue?

Re: Oil ash residue

Posted: Thu Apr 16, 2020 2:01 pm
by admin
Strange that he reset the oil ash value without a real cleaning of the filter. Now you have a wrong oil ash value so the ECU could be deceived. I don't know all the usages of this value in the ECU calculations, but I'm sure it's used to know the real life of the filter and its usage limit.

I think the more reliable way to check your issue is to read the error log related to the warning light stored in the ECU. If this error disappears immediately when the light is off, you have to connect VCDS or similar just when the light is on.
This error could say for example that the differential pressure sensor gives an implausible signal.