Is it not a symphony then?
Thought they were the only ones that come up with that code??
Assuming it is then.
You disconnect your battery to do what ever work needs doing.
On reconnecting if you get the EP-E02 code you will need to disconect the battery and wait at least ten minutes. then reconnect.
If your still getting the EP-E02 code then check t'other end of the wiring and or Disconnect the battery again and check for continuity ( battery to radio )