We will have no idea what engine is in your car, petrol diesel
Renault DF codes, most are specific to the car, but still need other info

 

Hi, if it`s diesel car, DF226 mean - damper valve circut (CC.1 short to + 12 V, CO.0 open or short to earth).

 

how this can be cured ? My inlet flap is always open( with or without engine on/off)

 

Also, what are the symptoms?

 

Should be a small black length of pipe going to it, this pipe forms a vacuum off the solenoid which then opens the flap, when engine is switched off, this vacuum is then released