what is the ECM/PCM IN FORD VAN 2007?

It sounds as if you are a beginner. ECM(electronic control module)PCM (power control module). Your best bet is to have somebody knowledgeable diagnose your running condition. A vibration at idle is usually an engine missfire. This should generate a service eng lamp. Never jump to conclusions. A vibration at idle could also be a faulty engine mount. More and proper information is necessary.Thorough diagnostics is the way to save money, not buying parts and installing them!