check injector message

Hi All I have a check injector error message on my 1.9 dci 04 megane that comes on then after a few mins if I restart the engine goes off but can come on at any time when restarting the service light also comes on the car starts first time every time and no problems with the engine runs fine. when checked for error codes old code p0670 when cleared could not get code to reappear, help any ideas just the latest in a long list of problems can find most answers on the forum but not this time