I drive a Kia cerato 1.5d from 2006. It runs ok, but from time to time it cuts out while I'm driving. It's a very strange problem. The car cuts and shuts down then it won't start again, but all I have to do is lock and unlock the doors. After this, it starts again and can run again for weeks without the slightest problem. I wonder if this a symptom of a bigger malfunction. Can anybody help me, please? Thanks.