A slow or NO drain condition will trigger an "F 02" error message.
If you wish to examine the pump strainer---unplug the washer and remove the (3) screws at the bottom of the access cover. This cover is on the front of the washer below the door.
Once removed--you'll see a removeable cap that is on the pump housing. Even if there is no visible water in the tub--you'll still need a few towels to soak up the inevitable gush of water when this cap is removed.
Check the strainer and the pump body for coins and other debris.
When done, re-install.
A restricted or blocked drain will NOT trigger an "F 11" error message.