the indicators have stopped blinking and there's no beep when I lock up using the remote, car still locks up fine. anyone any ideas if it's an easy fix?
The car (not the remote) battery is probably on the way out and not giving sufficient voltage to drive the locking system. Try locking with a good battery if you can find a spare one.
Did you get to the root of this? - my w202 did this when I took the rear door cards off to mess about with speakers.
I came to the conclusion that the rear door was registering as not properly closed because the plastic plate by the lock (which normally presses on the rear door switch when the door closes) was not in place.
All went back to normal after I put the door cards back on.
Perhaps one of your door switches has gone faulty?
My car behaves the same when any of the doors aren't closed properly, so I would guess that is the case or as previously stated one of the sensors thinks a door isn't closed.