Porsche Cayenne 958 DPF light still on after DPF cleaned.

[Saja]

Hi i was wondering if anyone could help and advise i have a cayenne 2012 3.0D the DPF light came up the other week coil light flashing and engine management orange light on and car since has gone into limp mode.. Very occassionally car has started without coil light flashing and not in limp mode but car is then missing firing/struggling to breathe. But as soon as you start to accelerate within 5-10 seconds car is back in limp mode and coil starts flashing.

I have tried manually clearing dpf with long drive in high revs by driving in manual mode adding various solutions into diesel tank designed to clean DPF but no luck.

In the end i have removed the DPF and cat have had them profesionally cleaned with any blockages cleared by one of these new machines.

When i have reinstalled the DPF the car still does the same and when i have tried to delete the fault codes they just keep reappearing saying DPF blocked.

Has anyone else experienced this or has any sensible suggestions on what to do next??

i Also have another code P227900 which is for a leak in the intake system any one advise where to start with this one??

thanks

PS very embarrassing being over taken by nissan PIXo as im struggling to hit 50mph up hill on dual carriage way.

[Slippydiff]

See the other threads about DPF issues on this very forum. Driving at high revs will NOT allow the DPF to regenerate, on the contrary it will only make the issue worse (as you’ve found out).
To make the DPF regen automatically (or indeed to manually force a regen) the engine needs several very distinct parameters to be met, these will differ from manufacturer to manufacturer and model to model, but having a certain amount of fuel in the tank is a fairly standard one.

The coolant temperature will need to be above a certain figure too.

The following will need to be functioning correctly :

Glow plugs, DPF temp sensor, DPF pressure differential sensor, cat pressure differential sensor, cat temp sensor, cat to DPF temp and pressure differential sensors. If ANY of these are faulty, DPF regen will not take place.

Good luck sorting the problem.

[Steve H]

^^^^^^ all this is correct but you also need to know that if you have fitted new (or properly cleaned) DPFs you will need to reset the DPF data as well as then clearing fault codes. The engine ECU calculates the state of the DPF and unless you can tell it there is a "new" one fitted it generally won't be happy.

This is not an OBD reader job, it will require some decent diagnostic kit (I'm not sure what you're using to read it with).

[Saja]

What would you recommend to use Launch/Snapon or anything else?? and how would i reset the dpf data to tell ecu new/cleaned dpf fitted

thanks

[Saja]

Steve H said:

^^^^^^ all this is correct but you also need to know that if you have fitted new (or properly cleaned) DPFs you will need to reset the DPF data as well as then clearing fault codes. The engine ECU calculates the state of the DPF and unless you can tell it there is a "new" one fitted it generally won't be happy.

This is not an OBD reader job, it will require some decent diagnostic kit (I'm not sure what you're using to read it with).

Hi Steve

What would you recommend to use snap on / launch and how would i clear the old dpf data to let ecu know that its been cleaned and reinstalled.

Thanks

[Steve H]

Not sure if either of those tools will do the trick but if they will you should be able to fine the % contamination in "live readings" and it will be a high amount. The reset will be in "special functions" or similar and you can check the live reading afterwards to make sure the reset has worked.

The special function will be listed as "replace DPF" or "reset DPF data" or something like that, if isn't there, the kit isn't set up to do it.