I apologise if this has already been answered in an earlier post but I did check through old posts. I have a 2005 206 hdi 110 (mileage 68k). For the last couple of weeks "UNBLOCK DIESEL FILTER" has come up on the central LCD display. As the car was going in for a service, I thought that changing of the fuel filter would rectify fault. Unfortunately it hasn't. The cars performance has not changed and no other warnings are showing. I've searched the internet but can not find anything to help me. The garage is just a local independent one with very little in the way of equipment. They do a good job normally but I don't think they have the knowledge to sort this problem. Would appreciate any help in this matter. If any more information is required, please ask. Thanking you in advance.