I will explain in this post how I got rid of the ''Risk of particle filter clogging'' error code P1490 on my Citroen C5 2.0, 163 CP, 2010.
I had to do the Periodical Technical Inspection here in Germany (TÜV) so I can still drive the car on the streets. I had an appointment at a service nearby me. They checked and tested all the systems, run the diagnostic with an OBD device, give me the papers and finish with the inspection. Everything went fine!
I left and went back home. In that evening I drove 60 km without a stop and with an average speed of 60-70km/h. Only 3 km in the city. While I was driving back from this location, the ''Risk of particle filter clogging'' error popped up on my dashboard. I have the car since 2 years and a half and it is the first time when I see this error! I have heard on forums that other guys had it, but that's it, never encounter it with my Citroën .
I knew that the car has to burn that soot (ash) that gets accumulated on the Filter, and the way to do this is to drive your car constantly with a speed of minimum 60 km/h for more than 10-15 minutes because that facilitates the car to do the regeneration process. What is strange is that at that moment I was driving with a higher speed than 60km/h, and the only thing that ai could think of was to so to set the transmission in Manual mode and increase the engine RPMs. I did so for a while, but I advice you not to do it, because, as I found out after, it doesn't help.
Second day I was driving to work. The error pops up again. Even though I was near the working place, I still drove a few more kilometers just to get rid of the error. It disappeared! so I could stop the car now and go to work. Later that day, on the way back home the same problem occurs! I knew that the car wants /needs to do the regeneration, but I didn't know it can't do it. I have decided to check it with DiagBox, start checking the Exhaust Line Information (in the main Fault Findings menu). Looking at the amount of the Eolys regeneration liquid, I saw that this wasn't the problem, but a bit below I have noticed that the '
'Authorization of regeneration' has the value set to ''
No''. Definitely this was the cause! But how to fix it?
I could not change it because it was blocked as default, so I start looking into errors. There I found an error regarding the Filter, but was dated long time ago, when the car had around 54k Km, now it has 190k. I have tried to delete it. It asked me if I am willing to choose an ECU Zone. As I've been informed by the same dialog box, ECU has 50 zones and after you fill all those 50, you cannot delete errors anymore. I agreed and pressed OK till the end.
I went back to the Exhaust Line Information and looked at the ''Authorization of regeneration''. This time the value was set to ''Yes''. So basically now the car is "allowed" to do the regeneration, because, I remind you, before it didn't have autorisation! Whom set it like that, I don't know!
Guess what! I drove to work. No ''Risk of particle filter clogging'' error appear! Drove back, no sign of any error!
Now, I don't know if it is just a big coincidence that I have never had this error and it happened to come up just now, without any connection with the fact that someone in the service has used the OBD device, or those guys from the Service actually did something to stop the regeneration so I will have to turn back to them to ''fix'' it and take my money for ''reparation'' or, even more likely, for a new filter because ''this one is full''.
I am really waiting for your opinion.
The error that I have deleted in DiagBox :