I had an engine management light come up, connected upto OBD, which indicated DPF. After some investigation found out that the filter should auto clean but the revs need to be above 3500rpm. I have a comfortmatic and the revs are never above 3000rpm in normal use. I took motorhome along road in manual at 3500rpm for about 5 miles, plugged into OBD and cleared the alarm. The fault has never returned. I now give the engine a blast once a year. See this post
https://www.motorhomefun.co.uk/forum/threads/fiat-ducato-dpf-sensor.110269/
The trouble with the claim in that thread is that it's a "they said" with no indication of proper attribution. Probably someone at a Fiat dealership, from the context, although that's not explicitly stated either. But who knows? I've plenty of experience of dealer technicians, service agents and parts department managers (not necessarily Fiat) telling the customer either what they think they want to hear, or just outright lies to try and make the customer go away.
I had an argument with a Volvo dealer who claimed that they couldn't have lost two of my wheel nut covers which were missing when I checked the car on their forecourt immediately after a service. They claimed that they must have been missing previously because they don't remove the wheels during a standard service. When I asked them why I had been asked to hand the wheel nut key to the service receptionist when I booked the car in, and how they had managed to obtain measurements of the inner and outer brake pad thicknesses at all four wheels to an accuracy of a hundredth of a millimetre, two new covers were suddenly produced from the parts department.
Another garage that claimed one of my locking wheel nuts was seized, that as a result they'd had to damage it whilst removing it and I would have to pay for a new set. I knew what they'd done because I'd actually had the same wheel off the car the day before, and torqued all the nuts correctly with a torque wrench and none were seized. But carelessly trying to spin a locking nut with an impact gun and letting it slip is another matter. My word against theirs though, and I had to suck that one up, but I let them know that I knew what had happened in no uncertain terms, and they lost any future business that I might have given them.
I could go on, but I'd only bore you all to death.
Regenerations on X290s are initiated by post injection of fuel into the cylinders to overheat the exhaust gases, and bring the exhaust temperature up to over 600C. As such they are just as achievable at 1500-2000 rpm as by revving the dogs danglies out of the engine, perhaps unlike some older implementations. It does however require the entire system to be working as intended, so if one part has malfunctioned or is not up to spec...
But on one hand, the manufacturer's warranty does specifically exclude filters. On the other hand, it might be possible to argue that a DPF has a normal life expectancy far beyond 1000 miles. So there could be room for discussion, or ultimately a legal challenge. There may be more chance of success with that argument in relation to a DPF than say, a clutch which could easily be wrecked by a customer in a day and would be difficult to prove one way or another, but still normally excluded from many warranties anyway. Nevertheless, would the warranty exclusion override any such argument, or might there be a realistic chance of success on the balance of probabilities?
But don't underestimate the amount of data that can be extracted from the engine control unit, much of which can be read with
MES.
If the customer is arguing that the DPF must have been faulty from new, but the data from the vehicle shows that it has completed one or more normal regenerations, never logged what would be considered excessive amounts of clogging beyond normal service expectations etc. even that becomes a complex situation. And I'm not suggesting that there is in this particular situation, but if the ECU has logged a driver over-revving incident or other driver induced abnormality, that's more grist to the mill. And any of that could be introduced by the dealer or manufacturer if such data exists.
So "they have to put it right" unfortunately doesn't hold water, and these issues can become quite complex very quickly.
