Depollution warning self cleared - info only.

[Pavl]

This is just to add to the knowledgebase for those who get the depollution warning .... sorted itself out ... here are the circumstances.
Approx 40 minutes fast dual carriageway (3000rpm) on downhill to motorway junction - light comes on.
Followed by over an hour of fast motorway (3000rpm) - light remains on.
Third or fourth start two days later and light goes out.
C5 x7 basic 1.6 FAP/DPF 2008.
Fuel tank was over half full.
New air doser two years ago, Eolys diagnosed September as having more than 1.5 litres and with no other faults.
Normally does very long runs at 130+kmph, MOTs very clean.

Recent change in driving patterns so that it was running weekdays on very short/stone cold journeys then weekends with long high speed runs over two hours.

Not offering any ideas ... just info in case it helps the wizards with someone else in same situation.
Paul

[GiveMeABreak]

Hi Paul

If the 'Risk of Particle Filter Clogging' warning comes on, this is the first indication that the engine ECU has tried multiple attempts to regenerate the filter unsuccessfully. So the advice is as you have done, to take if for a long run to allow the engine to get to operating temperature and for the exhaust gasses to get hot enough to attempt an uninterrupted regen. If you are successful then all should be well, but if it continues and you are already doing normal driving runs that are not too short, then it may indicate the filter is nearing end of service life.

Can't remember if you told us how many miles the C5 has done, but this will also provide an indication.

[RichardW]

It's normal for the 'Depollution fault' (engine management light in general speak!) to go out after 5 starts if the fault is only temporary. Code will be stored in the ECU. Our 1.6 HDi used to put the light on if you lifted off quickly from high revs - something to do with the replacement EGR valve.

[Pavl]

Thank you "GiveMeABreak" and "RichardW".
Miles just over 158k and the short/cold runs are only very recent.
And plan to get it plugged in again at some point just to see what the code is.
Has been running without low speed fan apparently for years without any consequences.
Other than that never any faults other than the one leading to airdoser replacement.
Paul